(Srila Prabhupada in New York City, 1966—click to enlarge)
"The difference between a conditioned soul and a liberated soul is that the conditioned soul has four kinds of defects. The first defect is that he must commit mistakes. For example, in our country, Mahatma Gandhi was considered to be a very great personality, but he committed many mistakes. Even at the last stage of his life, his assistant warned, 'Mahatma Gandhi, don't go to the New Delhi meeting. I have some friends, and I have heard there is danger.' But he did not hear. He persisted in going and was killed. Even great personalities like Mahatma Gandhi, President Kennedy—there are so many of them—make mistakes. To err is human. This is one defect of the conditioned soul."
(Sri Isopanisad, Introduction)
"To err is human. A conditioned soul is very often apt to commit mistakes, and the only remedial measure to take against such unintentional sins is to give oneself up to the lotus feet of the Lord so that He may guide one to avoid such pitfalls. The Lord takes charge of fully surrendered souls; thus all problems are solved simply by surrendering oneself unto the Lord and acting in terms of His directions. Such directions are given to the sincere devotee in two ways: one is by way of the saints, scriptures and spiritual master, and the other is by way of the Lord Himself, who resides within the heart of everyone. Thus the devotee, fully enlightened with Vedic knowledge, is protected in all respects."
(Sri Isopanisad 18, Purport)
"The Blessed Lord said, 'Many, many births both you and I have passed. I can remember all of them, but you cannot.' That is the difference between God and man. That is the difference between God and man. We cannot remember. Even we cannot remember what I did at this time yesterday. That is our forgetfulness, is our nature. To commit mistake, to forget, to be illusioned, to be cheated, imperfection of the senses—these are our qualifications. Every one of us, anyone who is in this material world, they are subjected to these defects: he is sure to commit mistake—'To err is human.' "
(Srila Prabhupada Lecture, Columbus, May 9, 1969)
"One can understand what is God by the mercy of God, not by mental speculation. It is not possible. We have got very limited scope of knowledge. Our senses are imperfect, we are full of cheating propensities, and we are liable to commit mistake. These four defects are within us. However a great man one may be, he is sure to commit mistake. I shall give you one tangible example in the life of Mahatma Gandhi. You know he was a very great man, political leader in India. So he was also very God-fearing man, a very nice soul. But he also committed mistakes so many times. So to err is human. This is a fact in every person. Therefore, because we commit mistake, because we are sometimes illusioned, and because we have got a propensity of cheating others, and because our senses are imperfect, therefore, simply by mental speculation it is not possible to realize God. Then how one can realize God? That is mentioned in the Bhagavad-gita and other literatures, that by the mercy of God one can realize God."
(Srila Prabhupada Lecture, Boston, April 26, 1969)
"Krishna says to Arjuna that 'I am giving you perfect knowledge.' This is our process. We receive knowledge from the perfect person. There is no use getting knowledge from imperfect person. That is useless waste of time. And who is perfect person? Who does not commit any mistake, who is never illusioned, whose senses are not imperfect and who is not a cheater. These are the qualification. These are the symptoms of perfect person. First thing is he does not commit mistake. Throughout the whole world you study big, big men, they committed mistake. Hitler committed mistake. Gandhi committed mistake. Churchill committed mistake. Because 'To err is human.' However big you may be, you cannot avoid mistake, because you are not liberated. So these are the signs of becoming perfect man: that he does not commit mistake, neither he is illusioned."
(Srila Prabhupada Lecture, Nairobi, October 28, 1975)
"Devotee of Krishna, he does not say anything as his own opinion. He never says. What Krishna says, he says. He may be not perfect, but what Krishna has said, that is perfect. Therefore a pure devotee, who does not say anything beyond which was spoken by Krishna, therefore his statement is also without mistake. Common man within this material world, he commits mistake: 'To err is human.' Even big, big personalities, they commit mistake. But narayana parah. He is transcendental. Krishna is transcendental. There cannot be any mistake; there cannot be any illusion.
Those who are within this material world, they have got four defects: they commit mistake, they are illusioned, and their senses are imperfect—bhrama, pramada, vipralipsa—and they're cheaters. Because... Just like modern-day scientists and philosophers, they propagate so many branches of knowledge, but when, on the crucial point, they are caught, they say, 'I, I do not know perfectly. I do not know perfectly. We are trying to know. In future, we shall tell you the perfect.' But if you are not in perfect knowledge, why should you take the post of a teacher? If your knowledge is imperfect, then whatever you speak, that is imperfect. Therefore with imperfect knowledge, why you should become a teacher? That is cheating. That is cheating."
(Srila Prabhupada Lecture, London, August 3, 1973)
"Just becoming initiated as Krishna's devotee puts him in the topmost category of human society: sa buddhiman manusyesu, sa yuktah krtsna-karma-krt: (BG 4.18) 'He is intelligent among human society, he is in the transcendental position, although engaged in sorts of activities.' And such devotee, no matter he has not advanced yet to the highest level of spiritual understanding, still he is to be considered the most exalted personality never mind he has got any temporary frailties:
api cet suduracaro, bhajate mam ananya-bhak
sadhur eva sa mantavyah, samyag vyavasito hi sah
'Even if a devotee commits the most abominable actions, he is to be considered saintly because he is properly situated.' As you will say, 'To err is human,' so in the neophyte stage we may always expect some discrepancies are there. Kindly see the things in this light and forgive their small mistakes. The big thing is they have given their life, everything to Krishna—that is never a mistake."
(Srila Prabhupada Letter, April 30, 1973)
"We ordinary human being, we have got four defects. First of all we commit mistake. Even big, big men, they commit mistake, because to err is human. Committing mistake is not a disqualification. As a human being, he is prone to commit mistake, everyone accepts."
(Srila Prabhupada Lecture, Manila, October 12, 1972)
"After all, we commit so many mistakes. That is human nature. To err is human. That is not fault. But try to rectify with cool head. That is required."
(Srila Prabhupada Lecture, Calcutta, January 27, 1973)
"To err is human. Anyone commits mistake. There is no doubt about it. But after committing mistake, if I stick to that mistake, that is foolishness. When it is detected that it is mistake, you must admit. That is greatness."
(Srila Prabhupada Morning Walk, Bhuvanesvara, February 1, 1977)