The Heights - 7:89
"If we return to it after Allah has delivered us from your religion, we would be ascribing a lie to Allah. We cannot return to it unless Allah, our Lord, wills it. Our Lord encompasses all things with His knowledge. We put our trust in Allah alone. Set between us and our people with the truth, O our Lord. You are the best of revealers.
Those who are under oppression and persecution may keep their faith secret if there is no way out:
The Family Of Imran/3:28
Let not the believers leave the believers and take the disbelievers as friends. Whoever does that has nothing to do with Allah. Except when you fear them. Allah warns you about Himself. The return is to Allah.
The Bee/16:106
Those who disbelieve in Allah and open their hearts to disbelief after faith, except those whose hearts are full of faith but are forced to disbelieve, have deserved wrath from Allah and for them is a painful torment.
The Forgiver/40:28
"A believing man from Pharaoh´s side who concealed his faith said, "Are you going to kill a man who says, ´My Lord is Allah´? He has brought you clear proofs from your Lord. If he is a liar, that is his problem; but if he is truthful, what he has told you will come true. Surely Allah does not love the liars who transgress."
The Prohibition/66:11
"Allah gives the believers the example of Pharaoh´s wife. She said, "My Lord, build for me a house in Paradise and save me from Pharaoh and what he did; save me from this unjust people"."