Will a Muslim be held accountable if he convinces a Christian of the falsity of his religion, leading the Christian to atheism?

There is no sin upon a Muslim if he invites a Christian to Islam, and explains to him the falsity of his corrupted religion, and then the Christian becomes an atheist after that. This is because the Muslim has fulfilled his duty of advising and inviting to Allah, and he is not harmed by what the Christian does. It is advised to avoid such hypothetical questions.