If you used to be a Christian and you stop believing, your Christian friends may tell you that you were never a real Christian. This idea shows up in I John 2:19.
This is what was said to me. "You weren't really a Christian. Not really." And they'd tell the parable about the sower and the seed, you know, where the seed springs up quickly, but doesn't have enough water, so it dies (Matt. 13:3ff).
Well - if they mean that I was never a real believer, they are wrong. I know what was going on in my mind, and they don't.
I don't mean to brag, but when I was a practicing Christian (for several decades), I studied the Bible in its original languages, teaching myself to read Hebrew and Greek; invested hundreds of dollars in Bible reference books; and memorized hundreds of Bible verses, most of which I still remember. I engaged in personal evangelism, in the United States and in a couple of foreign countries. I taught Sunday School and led Bible studies. I once spent hours going head to head with the pastor of a church whose ideas (I thought) were unscriptural; I stood my ground, and I proved him wrong. I was 19 years old at the time.
Eventually I had a large collection of English Bible translations - 62 of them.
In other words, I was the real thing. To this day, I'd match Bible knowledge with any Bible-thumper.
I remember when my deconversion began.
It was in 2018. At my (Baptist) church, we had a list of cancer patients in our church. Each Sunday, we would pray for the cancer people by name. After a certain amount of time (a few months), each one would die. Always. Nobody was healed.
I was teaching a Sunday School class (adults age 60 and above), and at the end of each class we would pray as a group. I was expected to "lead the closing prayer."
Some of the people on the cancer list were friends of mine. They were real to me. One memorable Sunday morning, I was doing the "closing prayer," and I said, "Lord, please heal Brother Jeff ... and please heal Brother McKenzie ..."
And it suddenly dawned on me that God is unlimited. If he really exists, if he is really the God we read about in our Bible, then his power is unlimited (Jer. 32:27). He created quarks and neutrinos and dark matter and black holes. He keeps the stars in place.
I found myself standing in front of this solemn group of conservative white-bread Baptists praying, "And Lord, please heal all the cancer patients in all of the world, everywhere. And please make cancer stop. Completely. You can do anything. Make it so that we don't ever have to look at a cancer list again. Amen."
After that prayer, nobody looked me in the eye. They seemed to be nervous.
Time passed, and I did some serious thinking. I had studied the Bible enough to know that it contradicts itself. I knew that prayer was a failure, 100% of the time, unless you prayed for something like the weather, which is pretty unpredictable.
God did not stop cancer. God did not heal one single person on the cancer list.
Paul said, "Examine yourselves, to see whether you are in the faith. Test yourselves (II Cor. 13:5)". I started doing some serious thinking.
I bailed out of my Sunday School position; I gave the pastor some excuse. Time passed, and I did a lot more thinking. I started skipping church on Sunday morning, and I finally just quit going.
Inside me, in my mind, there just wasn't any BELIEF in a god. It was like looking into a box that used to have a basketball in it, but now there's no basketball.
I didn't start hating God or hating religion or hating Christians. Most of the people in my family are professing Christians, and they are good folks.
(And like most Christians, they do use profanity, but not as much as I do, and they do fornicate, but they're sneaky about it, and they are capable of petty hatreds. I guess they ask God to forgive them.)
After a few months, my pastor called me - left me a message to the effect that he hadn't seen me in church in a while, and wondered if anything was wrong, and offered to meet me for breakfast at the local fast food eatery.
I returned his call and told him we had a lot to talk about. I set up the meeting for breakfast at McDonald's the following morning.
We sat down together and ate McMuffins. I told him straight out that I had stopped believing in God. He was very surprised, and asked if somebody at our church had offended me. I assured him that this was not the case (I wanted to say, "God has offended me by pretending to exist when he doesn't" ... but I didn't say that).
So ... was I ever a real Christian?
If you mean, "Did you have a personal experience with the risen Christ?" the answer is NO. I don't believe in the resurrection of Jesus. I don't believe that Jesus ever actually lived.
But I was (at one time) a sincere believer. I swear to your god.