(Srila Prabhupada installing Radha London-Isvara, 1969—click to enlarge)
"The secret of success in Krishna Consciousness is to render service to Krishna to the best of our capacity. There is no other alternative to this. The more we render service therefore, the more we are able to advance.
Regarding your feeling yourself as unqualified, whatever you can do, then do it, but you should try your best for Krishna. This is important. Ultimately everything is depending on Lord Krishna. You just have to always remember this."
(Srila Prabhupada Letter, June 27, 1969)
"Do your best to serve Krishna and he will give you required intelligence to cope with disturbing situations."
(Srila Prabhupada Letter, September 15, 1967)
"In the conditioned stage there is every possibility of being mistaken; but Krishna will always protect us if we are sincere; even if there is a gross mistake, Krishna forgives his devotee who is very sincere so go on working sincerely and Krishna will protect you always."
(Srila Prabhupada Letter, August 29, 1967)
"You should try your best and with Krishna's help—Krishna will help you. If you keep your heart in that attitude, that you want to become a pure and sincere devotee, you must be a sincere devotee. And Krishna will help you. You have to keep your heart in that way, that is your business."
(Srila Prabhupada Letter, November 23, 1968)
"So far as your duty is concerned, you are doing your best. That is your spiritual qualification. The best qualification for a Vaisnava is to act sincerely, and to his best capacity, for the service of Krishna. Otherwise, Krishna is so great, and we are so small, there is no question of our giving any service to Krishna. But Krishna is so great, and He is so greatly merciful, that any small service we offer to Him in devotion and sincerity He will accept. Krishna does not require anyone's help or service, but if we serve Him, even in a very small capacity, He will accept it. So that is our only hope. One who can show the whole cosmic manifestation within the hole of His mouth, what service can we render unto Him? So the best thing is to employ all of our talents and energies in His service. That will help us to progress."
(Srila Prabhupada Letter, June 24, 1969)
"Actually, nothing in Krishna consciousness is an accident, but sometimes Krishna will put us into a seemingly unfavorable situation just to help us realize that he is the Controller. In the material world, all these situations are meant for tribulation, but in Krishna consciousness, they are meant for advancement. Kunti Devi is always praying 'Let the trouble come again and again, so that I may have the opportunity to surrender to You.' So to accept any situation as Krishna's mercy is to advance in spiritual life. You just try your best to serve Lord Krishna, and if any perplexing circumstances arise, just pray to Krishna to give you strength."
(Srila Prabhupada Letter, May 21, 1972)
"Everywhere it is difficult because people have become godless. Still, we have to try our best. The task is difficult, undoubtedly. It is very difficult task, to bring back people to God consciousness. But still we have to do it to satisfy God. He wants it."
(Srila Prabhupada Conversation, Rome, May 24, 1974)
"Never mind even it is imperfectly done, we must execute the orders of Caitanya Mahāprabhu, yāre dekha tāre kaha kṛṣṇa-upadeśa (CC Madhya 7.128). I may not be so very expert in delivering the message of Kṛṣṇa, but my duty is to try to my best capacity how to distribute this knowledge to the suffering humanity."
(Srila Prabhupada Lecture, Delhi, March 26, 1976)
"So try to understand the philosophy nicely and spread it to your best capacity so that these suiciding men can be saved as far as possible. It is not, however, possible to check the suiciding policy of the modern society, but my Guru Maharaja used to say that if he could save one person then He would consider His mission successful. Similarly, if we individually could save at least one person, many of the suiciding men can be saved.
So do your best and Krsna will give you necessary intelligence and help, and try to push on this Movement as far as possible."
(Srila Prabhupada Letter, June 17, 1970)
"So this is our Kṛṣṇa consciousness movement, to distribute perfect knowledge, Kṛṣṇa consciousness, and that will make the whole world happy. So try to distribute this knowledge to your best capacity. Kṛṣṇa will recognize you, that you are trying your best to work on His behalf because He comes down to distribute the knowledge. Yadā yadā hi dharmasya glānir bhavati bhārata, tadātmānaṁ sṛjāmy aham (BG 4.7). Because we are all His sons—we are suffering—so He wants to see that our sufferings are mitigated immediately."
(Srila Prabhupada Lecture, Miami, February 25, 1975)
"As a military man, Arjuna fought to his best, but the victory was brought him by Krishna. Similarly, we should try our best to our best capacity, and victory will come from Krishna. We should never sit idly and ask Krishna to do everything. That is the teachings of the Bhagavad-gita. It is clearly said in the Gita: 'Yuddhasya ca mam anusmara (BG 8.7).' So ordinarily, we have to try our best to our best capacity to achieve something, and by Krishna's Grace, all of a sudden we shall see everything is there. This sort of help from Krishna is transcendental happiness."
(Srila Prabhupada Letter, February 20, 1968)
"If we remain sincere to Kṛṣṇa, that is our victory, not the result. Karmaṇy evādhikāras te mā phaleṣu kadācana. We have to act according to direction of Kṛṣṇa, that much. We want to see good result. Even there is no good result, we don't mind. We must be sincere to Kṛṣṇa that 'We have done our best.' That's all. Without cheating Kṛṣṇa. That is our duty. As servant, we shall not cheat the master. Result, no result—that depends on Kṛṣṇa. We should not be sorry if there is not result. Never mind."
(Srila Prabhupada Conversation, Allahabad, January 11, 1977)
"Never mind where you are situated. We are not concerned with a particular place or country or society. We are concerned with Kṛṣṇa. And everything belongs to Kṛṣṇa, wherever we go. We are here.
We are not in Japan; we are in Vaikuṇṭha, this temple. We are in Vaikuṇṭha. And we are doing the service of Kṛṣṇa, that Vaikuṇṭha service. So in this way, with this attitude, go on preaching. I am very pleased that you are doing your best. That I want."
(Srila Prabhupada Lecture, Tokyo, April 20, 1972)
"You should not be discouraged if people are not coming to your meetings. We are trying to please Krishna. That is all. We simply must go on with our business, to the best of our ability. We must always sincerely try to do our best with great determination. This is the transcendental position. Success or failure, this is not our business. We leave that up to Krishna. My Guru Maharaja said, it does not matter if anyone comes to hear. You go on with your chanting. If no-one hears you the walls will hear. But this does not mean that we should sit down someplace and simply chant Hare Krishna for our own benefit. We should be always anxious to save the cripple minded people with the science of Krishna Consciousness. This is the position of a Vaisnava."
(Srila Prabhupada Letter, February 15, 1973)