This is dishonesty.

Prabhupāda: Yes. Ācārya means he must show by example. Āpani ācari bhakti śikhāimu sabāre. Hare Kṛṣṇa...
Umāpati: Is there such a thing as a sincere atheist...
Prabhupāda: Eh?
Umāpati: ...who benefits by austerity?
Prabhupāda: Atheist? Atheist? How he's sincere?
Umāpati: That's what I... That's what I'm asking.
Prabhupāda: Honest thief? It is contradictory. If I say, "Here is an honest thief," is that a good designation, honest thief?
Umāpati: Well, in that case, that's so. You're right. It's absurd. Yes.
Prabhupāda: So...
Yaśomatīnandana: A sincere atheist...
Umāpati: But there are those who appear... At least, they think, they feel they are sincere when they go through austerities, but they won't accept Kṛṣṇa consciousness as, at this point in their, in their existence.
Prabhupāda: No, some atheists say that "We are Godless because nobody has convinced us about the existence of God." That is honesty. That is honesty. But there are rascals, however you may convince him, he'll not take it. That is rascaldom.
Yaśomatīnandana: Believe in God.
Prabhupāda: Yes.
Hṛdayānanda: So the honest ones become devotees?
Prabhupāda: Yes.
Hṛdayānanda: We were all...
Prabhupāda: If he's honest, then he must take.
Yaśomatīnandana: We were all atheists, Prabhupāda.
Prabhupāda: Eh?
Yaśomatīnandana: We were all atheists.
Prabhupāda: Yes. If you, if, if, if an atheist is honest, then when he's convinced, he must accept Kṛṣṇa. That is honesty. If after convincing him, he does not take, that is dishonesty.
Umāpati: Yes.
Prabhupāda: This is dishonesty.

 Morning Walk -- December 5, 1973, Los Angeles