Q: Can a person say they believe in Jesus, but deny other aspects of God’s truth (like hell), and still call themselves a Christian?
A: Technically, yes — people can call themselves anything they want and believe anything they want. But that doesn’t mean they are! Additionally, knowing what we mean by ‘believe’ is important as well to answering this question. I’m assuming you’re using ‘believe’ here in a way that is more than mere intellectual assent to the existence of God as One, which is what demons, while trembling, possess (James 2:19). Yet, they are obviously not born again.
So, to get to the heart of the question, can someone actually put their faith in Jesus yet not believe other things in God’s Word? Maybe what you’re wondering is this — what are the non-negotiable essentials for true salvation?
I believe the Bible teaches, throughout both the Old and New Testaments, that the person and work of Jesus is the absolute essential nugget that one must believe in order to receive God’s saving grace (i.e., who he was and what he did). This is seen in how the Old Testament people were to look forward to the coming Christ (Isaiah 7), as well as how the New Testament people were to respond to already-came Jesus (Acts 2). In both cases, Christ Jesus was the God-man who came to save all who would believe by offering himself up on the cross as the sufficient sacrifice for our sins, then was bodily raised by the power of his Father, and visibly ascended back to glory where now he lives. This is the confession that is required for one to be saved (Romans 10:9-10, 1 Cor. 15:1-4).
Still, the question remains — when confronted with other biblical, quite essential truth, can someone reject it and still genuinely be a Christian? Here’s a good principle to follow: Genuine Christians accept God’s truth because they are born of him. That’s why they listen to it (1 John 4:6). So when biblical truth is presented, especially of an essential nature, authentic believers will receive it and adjust their life.
Take, for example, a new believer. While a biblically-based, Jesus-centered confession is the gateway to conversion, one of the evidences of it will be the willingness to believe further truth when presented. One may not know all there is to know about, say, hell or the Holy Spirit, but as the truth is taught, genuine believers will readily accept God’s Word and rest in his truth. (1 John 4:6).
So perhaps the best answer to the question is this: Not believing other important biblical truth may not stop you from claiming to be a Christian, but your continued rejection probably reveals you’re actually not what you claim to be.