” he must be a lapsed Muslim.”
As most people calling themselves Christians are “lapsed christians” because they don’t believe the Bible is the word of God, and therefore don’t believe every word in the Bible literally, and don’t live by every word.
That’s what a missionary friend believes.
To each his own.
He can call himself whatever he wants but the true believers-—those who accept the Koran as the word of Allah, which is preached in every mosque in the US and around the world-—have their own words for that type, namely “apostate” and “infidel” and view them as subject to violent punishment.
That’s a different situation than what is faced by wishy-washy Christians, Jews, Buddhists, or whatever. Those faiths all preach peace and love in their own way and don’t take revenge on people who leave their numbers. Islam, on the other hand, calls itself peaceful but is in fact a belief system full of warfare, hate, murder, lust, misogyny, and brutality. It is the only “religion” on earth which proselytizes at the point of a sword.
It SHOULD be a case of “to each his own” but people who leave Islam or merely criticize it have to deal with death threats and persecution of every sort. That creates a situation of “faking it” in Islamic countries where nominal Muslims go through the motions of outward observance and the women cover up-—all to avoid problems. Iran is a case in point.