Far from being a sentimental activity, devotional service is based on well-defined principles that systematically guide a practitioner to ultimate perfection.
Whenever there is a discussion about the relationship between science and religion, it usually ends in a stalemate: scientists accuse religionists of relying too much on faith, which they say is experimentally unverifiable, while religionists accuse scientists of relying too much on physical and chemical laws that, they say, fail to measure the emotions and sentiments of a conscious living entity. The scientists fail to address or even acknowledge consciousness and its attendant needs; religionists fail to provide a satisfactory scientific and logical explanation for the practices they follow. The stubborn refusal of scientists to experiment beyond mechanistic science and the inability of religionists to present religion as a bona fide science have only widened the gap between the two parties.
A study of the Vedic scriptures of ancient India, however, convinces the reader that religion is not merely a matter of blind faith but is an actual science, verifiable by experiment. Unlike conventional religions, which force their practitioners to accept dogma based on faith, the Vedic religion (also known as sanatana-dharma, bhagavata-dharma or “Krishna consciousness”) repeatedly prods its students to inquire and question at every step. Sentimental practice is never encouraged. All religions, we know, teach us to love God and to serve Him. The beauty of the Vedic scriptures lies in their ability to explain the dynamics of this spiritual relationship by revealing the precise, well-defined principles that underlie it. A deeper understanding of this subject will nourish the faith of the faithful and satisfy the intellect of the intellectuals.
1. The Law of Attraction
Newton’s law of gravitation states that every body of mass in the universe attracts every other body of mass with a certain force. If m1 and m2 are the masses of two bodies separated by a distance r, then both will exert the same attractive force F upon each other. The force will reduce as the distance between them increases. According to the spiritual law of attraction, every spirit soul is attracted towards the Supreme Soul, Krishna. Being an eternal part of Krishna, we are constitutionally meant to love and serve Him. Nitya-siddha krishna-prema ‘sadhya’ kabhu naya/ sravanadi-suddha-citte karaye udaya (Caitanya-caritamrta, Madhya-lila 22.107). All we need to do is uncover this loving propensity by practicing devotional principles. Just as iron filings get attracted to a magnet, all of us in our pure state have a natural attraction towards Krishna. Lust and many other unwanted things prevent the full exhibition of these loving feelings, just like rust covers iron. 
The spiritual law of attraction differs from Newton’s law in some areas. Whereas the attractive force exerted by each mass on the other is the same, the attraction (in this case, the affection or love) that Lord Krishna has towards the wayward spirit souls is much greater than what those souls have towards Him. Srila Prabhupada writes, “He [Krishna] is just like an affectionate father, who is more eager to see his son than the son is to see him. There is no contradiction in such a quantitative difference in affection.” (Mukunda-mala-stotra 1, purport)
The attraction between Krishna and His devotees is unaffected by the physical distance between them, unlike the attraction between two physical masses. Other material barriers, like the language in which a prayer is intoned, one’s social or financial standings, or any other mundane criteria, have no effect on this spiritual relationship.
vyadhasyacaranam dhruvasya ca vayo vidya gajendrasya ka
kubjayah kim u nama rupam adhikam kim tat sudamno dhanam
vamsah ko vidurasya yadava-pater ugrasya kim paurusam
bhaktya tusyati kevalam na ca gunair bhakti-priyo madhavah
“Where were the hunter Dharma’s piety, Dhruva’s maturity, and Gajendra’s knowledge? Where was Kubja’s beauty? Where was Sudama’s wealth? Where was Vidura’s noble birth? Where was Ugrasena’s chivalrous strength? Lord Madhava is pleased only by devotional service and not by material qualifications.” (Sri Padyavali 8)
In sharp contrast to Newton’s law, the attraction between Krishna and His devotees has been known to increase with distance. Love in separation from Krishna is described as the highest form of love, higher even than love in union with Him. The most exalted devotees, the gopis of Vrndavana, experienced this form of love. After first enjoying a decade of Krishna’s association in Vrndavana during His early pastimes, they later had to undergo a century of separation from Krishna while He spent His time in Hastinapura and Dvaraka. All the while, their love for Krishna kept increasing, and finally reached its culmination, despite the fact that they were separated by a great physical distance.
Bhakti, or loving devotional service, is known as sri-krishnakarsini, “that which attracts Krishna.” Srila Bhaktivinoda Thakura writes in Jaiva-dharma, “The devotee whose heart is infused with suddha-bhakti attracts the attention of Krishna along with that of all His close associates by the power of his love. Love is the only way to conquer Sri Krishna, no other means are viable.” Prahlada, although a five-year-old boy, by the power of his devotion could attract the Supreme Lord Narsimhadeva, who appeared just to protect His dear devotee. Between a magnet and iron, it is the magnet that has the power to attract, not the iron. But with bhakti the devotee, who is an infinitesimal spirit soul, can attract the Infinite, all-powerful Krishna. 
2. The Law of Reciprocation
The law of karma states that for every action, there is an equal and opposite reactionwhich is very similar to Newton’s third law of motion. However, this karmic lawan aspect of material nature, which is working under Krishna’s direction – is universal; it does not act merely in the realms of physics or chemistry. Pious actions result in pleasurable reactions, while sinful actions lead to hellish sufferings.
In the Bhagavad-gita (4.11), Krishna says, ye yatha mam prapadyante tams tathaiva bhajamy aham: “As all surrender unto Me, I reward them accordingly.” To those who consider God to be impersonal, the Lord reveals Himself as the impersonal Brahman. To yogis who meditate on the form of the Lord within the heart, Krishna reveals Himself as the Paramatma, the Supersoul, who resides in the heart of every living being. But to those who accept Krishna as the Supreme Personality of Godhead, Krishna is eager to reveal His supreme form of sac-cid-ananda-vigraha – the Lord’s eternal personal form, possessed of full knowledge and bliss. 
When Krishna entered the wrestling match that Kamsa had organized in Mathura, He appeared differently to different groups of people.
mallanam asanir nrnam nara-varah strinam smaro murtiman
gopanam sva-jano ‘satam ksiti-bhujam sasta sva-pitroh sisuh
mrtyur bhoja-pater virad avidusam tattvam param yoginam
vrsninam para-devateti vidito rangam gatah sagrajah
“The various groups of people in the arena regarded Krishna in different ways when He entered it with His elder brother. The wrestlers saw Krishna as a lightning bolt, the men of Mathura as the best of males, the women as Cupid in person, the cowherd men as their relative, the impious rulers as a chastiser, His parents as their child, the king of the Bhojas as death, the unintelligent as the Supreme Lord’s universal form, the yogis as the Absolute Truth and the Vrsnis as their supreme worshipable Deity.” (Bhagavatam 10.43.17)
Fully surrendered devotees of Krishna experience the greatest reciprocation from the Lord. The Caitanya-bhagavata describes the story of Vasudeva Datta, a greatly powerful devotee of the Lord. Feeling extreme pain to see the sufferings of conditioned souls, Vasudeva Datta requested Lord Caitanya Mahaprabhu to let him suffer for the sins of everyone in the universe. The Lord was so pleased by Vasudeva’s compassion that He said, “This body of mine belongs to Vasudeva Datta…[He] may sell Me wherever he likes.” (Caitanya-bhagavata, Antya-khanda 5.27–28)
Devotees are ready to sacrifice everything for the pleasure of the Lord, and the Lord is ready to give Himself to His devotee. Srila Prabhupada writes, “This transcendental reciprocation exists because both the Lord and the devotee are conscious. When a diamond is set in a golden ring, it looks very nice. The gold is glorified, and at the same time the diamond is glorified. The Lord and the living entity eternally glitter, and when a living entity becomes inclined to the service of the Supreme Lord he looks like gold. The Lord is a diamond, and so this combination is very nice.” (Gita 9.29, purport)
3. The Law of Subjugation
As the master of the universe, Krishna controls everything and everyone. But one who has bhakti can control Krishna by love. Bhakti-yoga therefore is superior to all other spiritual practices, like karma-yoga, jnana-yoga, or astanga-yoga. 
The story of King Ambarisa and Durvasa Muni reveals this point clearly. Durvasa Muni had attempted to kill the pious Ambarisa for an insignificant offense. But Ambarisa remained unfazed and took complete shelter of the Lord. To protect His dear devotee, the Lord released his personal weapon, the Sudarshana chakra, and destroyed the demon Durvasa had sent to kill Ambarisa. The chakra then started chasing the Muni to kill him as well. Durvasa fled the scene and approached various demigods for help. Unable to get shelter from anyone, including Indra, Brahma, and Shiva, the great mystic finally approached Lord Vishnu in Vaikuntha, requesting the Lord to withdraw the scorching chakra and thus save his life. To his surprise, the Lord expressed His inability to protect him and ordered him to beg forgiveness directly from Ambarisa. He said:
aham bhakta-paradhino
hy asvatantra iva dvija
sadhubhir grasta-hrdayo
bhaktair bhakta-jana-priyah
“I am completely under the control of My devotees. Indeed, I am not at all independent. Because My devotees are completely devoid of material desires, I sit only within the cores of their hearts. What to speak of My devotee, even those who are devotees of My devotee are very dear to Me.” (Bhagavatam 9.4.63). Only after being forgiven by His devotee, the Lord assured, would the chakra stop chasing Durvasa.
As a small child, Krishna would dance like a puppet when the elderly gopis of Vrindavana clapped their hands. During the rasa-lila, sometimes the gopis would sing and Krishna would dance just to please them. 
Pure love of God is of the nature of Krishna’s internal potency, which is personified in Srimati Radharani. That pure love therefore has the power to bring the greatest person under His devotee’s control. The Pandavas, for example, bound Krishna with pure affection and kept Him always near them.
yuyam nr-loke bata bhuri-bhaga
lokam punana munayo ’bhiyanti
yesam grhan avasatiti saksad
gudham param brahma manusya-lingam
“My dear Maharaja Yudhisthira, all of you [the Pandavas] are extremely fortunate, for the Supreme Personality of Godhead, Krishna, lives in your palace just like a human being. Great saintly persons know this very well, and therefore they constantly visit this house.” (Bhagavatam 7.10.48)
4. The Law of Unification
The perfection of bhakti-yoga lies in dovetailing all of our desires for the pleasure of Krishna. In other words, a devotee sets aside all selfish motives and wishes to fulfill the desires of Krishna. In this way, the desires of both Krishna and the devotee are one. Whenever such a devotee speaks, he is speaking on Krishna’s behalf, presenting whatever the Lord would Himself say.
Devotional service to Krishna is so sweet that the devotee and the Lord sometimes forget their personal identities. They are so much in tune with each other that there is no difference in their purposes. Ye bhajanti tu mam bhaktya mayi te tesu capy aham: “[W]hoever renders service unto Me in devotion is a friend, is in Me, and I am also a friend to him.” (Gita 9.29)
Again, in the story of Ambarisa and Durvasa, the Lord makes this famous statement:
sadhavo hrdayam mahyam
sadhunam hrdayam tv aham
mad-anyat te na jananti
naham tebhyo manag api
“The pure devotee is always within the core of My heart, and I am always in the heart of the pure devotee. My devotees do not know anything else but Me, and I do not know anyone else but them.” (Bhagavatam 9.4.68)
It is important to note that the oneness attained by a devotee is different from the oneness impersonalist philosophers imagine they will attain by merging with the Supreme. A devotee rejects such oneness as hellish because it means the end of his individual identity, and thus the end of his chance to serve the Lord. Srila Prabhupada gives the example of a green bird entering a green tree. Deep within the branches and leaves, the bird may not be visible to an observer standing below, but the bird never loses its existence. It enjoys the tree’s fruits and flowers. A devotee who has returned to the spiritual world similarly enjoys service to Krishna with ever-growing freshness and sweetness under the shelter of Krishna’s lotus feet. 
Judge Your Progress in Bhakti
Rupa Gosvami, a sixteenth-century Vaishnava saint and a contemporary of Lord Caitanya Mahaprabhu, describes the systematic developments a devotee undergoes while practicing the science of bhakti. In the beginning, one has faith (shraddha)faith in some form of divinity or in saints or scriptures. This faith, which is compared to a seed, helps one to seek out the association of saintly devotees (sadhu-sanga), where the seed begins to mature and take root. Receiving nourishment in the form of hearing and chanting the holy names and glories of Krishna (bhajana-kriya) under the guidance of devotees, the seed grows luxuriantly. In the process, all the unwanted things in the heart that block the progress of bhakti go away, clearing the path for the creeper. 
Carefully cultivating spiritual practices and steering clear of all obstacles, the devotee achieves steadiness (nistha) in bhakti. At this stage, the waves of love of Godhead first appear. Continuing with spiritual practices, the devotee’s steadiness matures into intense taste (ruchi) for devotional activities, removing all threats of the recurrence of unwanted habits. Such a person is known as an uttama-adhikari.
Sivarama Swami, Srila Prabhupada’s disciple, based on the commentaries of past acaryas, writes in his Suddha-bhakti Chintamani about the advanced stages of pure devotion: “As devotees cultivate that taste, they develop concentrated attachment (ashakti) for Krishna. That attachment polishes the heart to such an extent that at times devotees think that Krishna has appeared there. At other times they intuitively understand their relationship with the Lord, though such realization is still immature.” (Suddha-bhakti Chintamani, page 303)
“At [the next stage] bhava, when they transcend the boundaries of matter, the touch of the pleasure potency immediately awakens pure greed in their hearts.” (Suddha-bhakti Chintamani, page 610) “Love of God (prema), the full manifestation of pure goodness, is like the sun. When a single but fully potent ray of the Krishna-sun touches a devotee’s heart, ecstatic devotion instantly becomes manifest. Just as a spark falling onto dry leaves quickly grows into a forest fire, one ray of pure goodness entering a devotees’ heart quickly flares into a blaze of love for God.” (Suddha-bhakti Chintamani, page 307)
Attaining the stage of pure love of God is the perfection of our existence, the goal of the human form of life. If we remain sincere, Krishna’s mercy is assured. Like any other science, if we stick to the principles and carefully avoid the dangers, we are bound to attain success in this life.
Mukundamala Dasa is a member of the BTG India editorial team. This article is based on a class given by Radha Gopinatha Dasa at ISKCON Mumbai.