just divorce her and leave her without insulting her. Here in Islam we believe in Evil and evils will try the most to not let a Muslim believe in God and evil will also try to let the Muslim man or woman do a mistake because we as Muslims know that evil had challanged God to let all people be sinners.
Some may ask why God did not get rid of the evil?
God gave evil chance to see those who will follow God and those who will follow evil.