We Are Having Issues Based On Religious Beliefs.

Good morning Aunty, please I need your urgent advice. I have been in a relationship since a year and some months now, my guy loves me and I love him too, but for the past few months now we have been having issues based on religious beliefs,
he is a Jehovah's witness while am a Pentecostal member.
He said that before he will introduce me to his mother, that I will join any of Jehovah witness within my vicinity which I refused because of their believe and I never knew that they are like this because they forbids many things that Pentecostal Church don't forbid. 
Please ma advice me, am confused I don't know the step to take right now and I don't want to make a mistake in marriage. Thanks ma God bless you for your good work.

You said that you never knew they were like that, now that you know please do not ignore what you have learnt about his place of worship. 
He has indirectly made his decision known concerning how he wish to raise his home. He won't permit you to worship in any other church except Jehovah witness and you must join his church if you wish to marry him. 
My question is, now that you have discovered that their doctrine and your doctrine differ, can you cope with his place of worship? Since you know that you can't join his church because of their belief, why do you still hold unto the relationship? 
The reality of marriage is that if there is no agreement between the couple, any misunderstanding may crush the marriage. 
Please don't ignore the obvious manifestation of your incompatibilities to avoid regrets in the future.