Do you think christians who turn to islam and become muslims...?

Because some see the 'fellowship of Jesus Christ, received the Holy spirit' thing as actually being a self delusion and self induced naturalistic experience,spurred on by great music, emotionalism, group think reinforcement. Some people leave and become muslims, some realisie that chances are all religions are just 'group think'. I think many of them may not have believed as strongly as I did if they just ended up as muslim, but i could be wrong.