This has been a really interesting thread, and OP I agree that this is a difficult situation for both you and your DH. My DH and I are both Christians and, whilst I hope we don’t conform to some of the stereotypes upthread, it does mean we are broadly on the same page in terms of what we say to the DC about God / heaven / Jesus / church etc. in that we teach them that as our faith and we hope and pray they’ll choose to own it for themselves one day but will love and support them regardless. We talk lots about other faiths and those with no faith, always as positively as we can but fundamentally they know we’re a Christian family.
Clearly if one of us lost our faith, or whatever words you want to use about that, it would mean a change in that dynamic and so I can see it being hard for both OP and her DH. As others have said, assuming this has been a gradual thing for the OP, then she has had a lot of time to get used to the change in her and DH will similarly need some time to process it, and to accept it. And I can understand him finding that process hard, and wanting to be sure that you’re sure - which absolutely doesn’t give him any right to pressure you or try to change your mind, but I suppose if it were me I might ask my DH whether he wanted to come to church occasionally just to see, and nothing would stop me praying for him.
I have known couples where this has happened and they have ended up splitting up - but in both of these cases, the loss of faith was part of a wider set of issues facing the marriage so it’s difficult to know whether the change in views on religion / faith / church on its own would’ve ended the marriage or not. That’s something only you can know I guess, OP - whether this is part of a wider dissatisfaction with your DH / marriage or not.
I don’t know if any of this is helpful, sorry if not!