Is singing non-muslim songs kufr and shirk?

Since very young age if you have been singing non-muslim songs and it has become habit so you can't stop singing songs. Sometimes songs are about other religions so it may include shirk and kufr words. I like to know is it major sin to sing songs like that? would it put you out of Islam? Please note I am not asking if singing is haram, I am asking would it put you out of Islam.