I'll be honest I don't know what you mean by religeously married. I can't imagine any religeous leader giving a blessing without a marriage.
And if 'religeous' ways of doing things mattered, why didn't you get married?
In any case, legal marriage is the only way of being married. Any informal blessing doesn't have any standing in social or legal terms.
I completely understand why that matters to you. If your DP knows marriage matters to you, what is his reason for not wanting to make that commitment?
If you have made any financial sacrifices as a result of being with your DP / having children (reduced working hours, reduced pay, reduced training ops, reduced promotion ops, reduced pension contributions) then you're in a dangerous position. Because if you split up, your DP will take with him all the benefits of being able to keep the same job (salary, promotion ops, pension etc) and you will not be able to recover any of it from him.
So, being married would give you the certainty that he intends to stay with you, the 'position' of being married (if that is important to you), and financial protection if things go wrong.
If you want to get married and he doesn't, you need to understand why. Is it because he doesn't want to commit to you? Is it because he doesn't want to have to share hsi money if you split? If he comes up with 'it's just a piece of paper' then you know you're in trouble. Because a) it really isn't, it's a life-changing decision, and b) if it was just a piece of paper, he wouldn't mind doing it would he.