One of my secret joys is building LEGO sets with my kids. It doesn’t matter what we’re building, I just enjoy the whole process—the instructions, the endless hunt for those tiny last pieces, the thrill of the finished work. My daughter and I once spent days assembling a LEGO dragon with a long swooping tail and a fierce, sharp-toothed smirk. It was one of the most intricate sets we’d ever built, mostly because of all the twists and turns in the dragon’s body. When we finished the creation, she proudly displayed it on the top of her bookshelf.
Imagine the LEGO set is reality. Everyone receives the same set—the same pieces, the same manual, the same photo on the box top. But it’s up to each individual what they do with it. You can choose to build it according to the Designer’s intent, using the wisdom he provided in his Word—or you can do your own thing. You can even declare that no one designed it—it’s just a random box of blocks. You have that choice.
Why Essential Christianity Matters
But if the set is true, it can stand up to questioning. Every line in the manual can be scrutinized without threat. And if you choose to build it according to the designer’s intent, you will have a strong and robust structure that the fiercest wind (or little brother) won’t be able to demolish. If you believe the truth about reality, your faith will not be misplaced.
In a LEGO set, not all pieces have the same importance. Some blocks could break off without anyone even noticing. Some you could remove or switch out without changing the overall structure. You could even put a few of the final blocks on backward or on the wrong side without weakening or significantly changing the final product. But those foundational blocks—the ones upon which the rest of the set is built—those are crucial to get right. If you don’t put those in the correct place, the structure won’t stand or resemble the photo on the box top.
Likewise, as I researched historic Christianity, one of the most important questions I had to answer was this: What building blocks of our faith are the essentials; in other words, which ones are essential for salvation?
If you ask ten Christians what the essentials of the faith are, you are likely to get ten different lists. But aren’t all doctrines equally important? I see this claim on social media all the time. Paul the apostle has something to say about this. Let’s look at an early creed in 1 Corinthians 15:3-5:
For I delivered to you as of first importance what I also received: that Christ died for our sins in accordance with the Scriptures, that he was buried, that he was raised on the third day in accordance with the Scriptures, and that he appeared to Cephas, then to the twelve.
Paul wrote that these beliefs were “of first importance.” That means they were more important than others. In fact, they were the most important ones. These essential beliefs united Christians everywhere. Every Christian affirmed them. I found myself with a good starting point regarding essentials. But surely this isn’t enough. This creed says nothing about the deity of Jesus. It doesn’t mention monotheism or the Virgin Birth. It doesn’t touch on the sinlessness of Christ or his second coming. What was I to make of this?
The Core Beliefs of Essential Christianity
This is a question that led scholar Dr. Norman Geisler to study the essentials in regard to salvation. He spent years studying the question, What must one affirm in order to be saved? He studied the question biblically and traced it through church history. I’ll do my best to summarize his view, but for the whole enchilada, definitely pick up his systematic theology volume on sin and salvation.1
First, Geisler acknowledged that this question could be answered a bit differently throughout world history. Today we have God’s written Word—his final revelation. Abraham didn’t know everything God would reveal to Moses. Moses didn’t have access to the Gospel of John. Yet Old Testament believers were saved in the same way we are now: by grace through faith.
Eight Doctrines That Define Essential Christianity
Today we have God’s final revelation, and Geisler concluded that, according to the New Testament, the essentials one must believe (at least implicitly) in order to be saved are
1. human depravity (I am a sinner);
2. God’s unity (There is one God);
3. the necessity of grace (I am saved by grace);
4. Christ’s deity (Christ is God);
5. Christ’s humanity (Christ is man);
6. Christ’s atoning death (Christ died for my sins);
7. Christ’s bodily resurrection (Christ rose from the dead); and
8. the necessity of faith (I must believe).2
So for people to call themselves Christians, they must at least implicitly believe these eight things. There are certainly more truths about God that must exist in order for these eight beliefs to be possible. For example, if Christians have put saving faith in Jesus but haven’t heard of the Virgin Birth, they aren’t disqualified from salvation. But if they are truly saved, they won’t be able to deny the Virgin Birth (essential because it points to Christ’s deity) once they gain a bit more knowledge.
But what about the Bible? Is it necessary to believe the Bible is the inerrant and inspired Word of God in order to be saved? Believing in the Bible isn’t what saves you, but the gospel can only be fully known if the Bible actually is the inerrant and inspired Word of God.
Faith is trust in a person—Jesus. That trust is based on truth and evidence. You have to know some things about him in order to follow him and trust him. It’s not simply accepting intellectual propositions. Think about it this way. If you love someone, you want to believe the truth about them. Knowing and believing true things about them is not the same as simply accepting intellectual propositions.
As I took apart my metaphorical LEGO set and put the pieces back together, I discovered that those inner pieces were in the right place. Someone else might take apart their set to discover they were missing a core piece or had one in the wrong place. But as I began to put all the blocks back in their rightful places, the finished structure was stronger and more beautiful than ever. Today my faith stands strong against the stormy waves of doubt that challenged the existence of God, the reliability of the Bible, and the truthfulness of Christianity. It looks a little different than it did before, but when I look back on my entire life, I see God’s providential hand orchestrating every situation, guiding every step.
Living Out Essential Christianity Today
Studying the Bible can be daunting and confusing. But isn’t every treasure worth the hunt? There’s nothing better than feeling that your life is planted deeply in the truth of Scripture. Now I consider it a privilege to invite everyone I know on that journey of discovering God’s grace because it reaps immense rewards in people’s lives. I have seen it with my own eyes.
1. Or listen to his own summary in this lecture, “The Essentials of the Faith,” Education Underground, June 17, 2013, YouTube video, 52:29, https://www.youtube.com/watch?v=pjdy-VWXrik.
2. Romans 3:23; 1 Timothy 2:5; Ephesians 2:8-9; Romans 10:9; 1 John 4:2; John 3:16; 1 Corinthians 15:12; Acts 16:31; Hebrews 11:6.
Adapted from Another Gospel? Student Edition: A Lifelong Christian Seeks Truth in Response to Progressive Christianity by Alisa Childers, releasing in October 2025.
