I know that I can just tuck the comforter between footboard and mattress, but I like thick bedding and it's awkward. Below is a link of a picture of a similar type bed.
Consistent with the Bible, sex external of marriage is a sin. That doesn't mean God will ship you to Hell when you have intercourse. However in case you are a Christian as you declare, you should have a want to comply with God's will and please him.
I think cream or white linens would look best and most authentic, especially with a design along the top edge of the top sheet and pillow cases. You can tuck/stuff your comforter between the footboard and edge of the mattress; you don't have to tuck it under the mattress. You may want to do that only just before you crawl into bed, and leave it folded on top of the bed during the day. Fold it however many times you like and leave it covering as much as you like. You could have your top sheet and a thin blanket folded l/3 or l/2 -way down the bed and your thick comforter folded 1/4 or 1/3 at the bottom of the bed. That could give you two or three different colors if your sheets, blanket, and comforter were different colors. It is a nice look.
Hi - the thing is if you like thick bedding then this bed is not really for you. Because as you say the only thing you can do is tuck your bedding between the footboard and the mattress and obviously to be able to do this you need quite thin bedding. So, you have two options - you either get thin bedding or get another style of bed. Personally, I am like you with the thick bedding with quilts/comforters etc - so, it is not a bed I would go with. There are so many different designs on the market that you could go for - why not have a look around to see what you can see and like better to enable you to have thicker bedding? I will try to have a look to see if I can see anything that you might like, but I have to go out now - so will come back on later :)
