Will one who was the cause of another's repentance and cessation from sin be rewarded, even without the latter's knowledge, and what is his reward?

"Whoever points to good is like the one who does it." The reward is also written for whoever causes good to be done, even if unintentionally. This is indicated by the Almighty's saying: "Indeed, We revive the dead and record what they have put forth and their traces. And all things We have enumerated in a clear register" (Qur’an 36:12). And the Prophet, peace and blessings be upon him, said: "Whoever introduces a good practice in Islam, and it is acted upon after him, will have a reward similar to that of those who act upon it, without diminishing their rewards in the least." So, whoever does a good deed and is emulated by others, will be rewarded for that. The same applies to evil deeds.