I find that in recent times my rapture enthusiasm seems to have waned somewhat, and I don’t know why. I am starting to fear that it is because I never had any true faith in Jesus at all, and am just deluding myself into thinking I’m a true Christian when I am just a false convert. Do you have any advice for me?
Yes I have. Get back into the word and review the promises the Lord made to you. You’ll find that if you asked sincerely the Lord granted your request for salvation and will never revoke it, no matter what. If you don’t know for sure that you were sincere when you asked, then do it again. It’s important to get this resolved, because the enemy has spotted a weakness in your defenses and is exploiting it. He can’t “unsave” you, but he can cause you to fear and doubt. That’s how he steals our joy. Try Matt. 7:7-8, John 6:38-40, Romans 10:9-10,13 and Titus 3:4-7.
You should also read 2 Cor. 10:3-5 and begin taking those thoughts of doubt captive and making them obedient to Christ.