Like I said you can't force your religion on anyone. Religion is a belief. That is something you choose.
Whether you like it or not, there are sets of laws that govern each religion. Whether the person chooses to believe or follow or worship or break those laws is irrelevant. They exist with or without his/her belief. Anyone can believe anything they want but Islamic Law dictates whether you are
born Muslim. Whether he or you choose to believe he is or not later on in life, irrelevant. Let him choose not to be Muslim, for all it's worth, or you can choose for him, but under Islamic Law, he may be Muslim. So he can preach I am not a Muslim, and he scream it from a Church or Synagogue, but the reality is, we have to check Islamic Law and whether it dictates whether he was
born Muslim and whether he could denounce it later. Let him convert to whatever he wants and not practice anything or everything. Irrelevant to whether he was born Muslim.