“his [alleged Christian] faith is very important to him, but it’s not something that is a topic of conversation every single day.”
As opposed to his DAILY public praise, promotion, protection, and proffering of Islam and its manifestations. Only thing missing is his public prayers - adhering to either religion.
Ask him who Abraham’s heir was. Few devious believers of any Abraham-derived religion would be clever enough to hedge the answer to conceal their true faith. A Christian would not hesitate to say “Isaac”; a Muslim would not hesitate to say “Ishmael” ... and that answer makes all the difference.
He doesn’t need public prayers.
His outreach to Muslims includes White House staff, who, I would bet, have a prayer room dedicated for them to pray times a day.
He doesn’t need to leave the White House.