My dad said he won't come to my wedding because I don't want a church wedding.

Continue to try. Invite him, wait until a moment he seems in good spirits to talk again, write him a letter, don't give up until you don't want to try anymore and then let him make his decision and focus on the important thing: you and your spouse.

Leave the door open for him. It's his problem if he misses your wedding, not yours.

You make what make you happy. If he does not attend and has said those hurtful things to you, I personally do not see much you can do about it. Stick with what makes you guys happy and let him decide what he wants to do for himself.

Things like this really piss me off. I lost my dad to brain cancer 27 years ago, and I hate to see anyone throw away a father / son or daughter relationship for trivial reasons. Regardless of which side causes it...I agree with the others, keep the door open and be the bigger person, as much as it hurts. Nice Christian behaviour. I truly hope he comes around and is able to beat the cancer. Good luck and I hope for better results.

On an alternative perspective, he's not well right now and maybe you could have a pastor or someone sign the paperwork you turn into the courts? I just know that unless it's a huge deal, I try to accommodate loved ones because, well I love them.

Assume he won't pay for anything, but if he chooses to miss his daughter's wedding, that's on him and he'll have to live with it. Surely it's not news that you're not religious?