In one sense, the gospel message is a simple one: Jesus died for the forgiveness of our sins and was resurrected on the third day. Yet, as simple of a sentence as that is, the truth and implications it contains are quite profound. Are we truly able to mentally grasp the truths of the gospel? What happens if we can't? What level of understanding is required of the gospel before being able to have faith enough to believe it?
Does a person have to fully understand the gospel to go to heaven?
Our understanding of the gospel comes by hearing it preached (Romans 10:13–17; Matthew 28:18–20) and having a heart that is open to the Holy Spirit (Acts 16:14). Paul describes the process of understanding the gospel as starting with preaching, which leads to hearing and understanding, followed by believing, and finally, reaching out to God for salvation (Romans 10:14). We have to understand the individual components of the gospel story in order to put our faith in the gospel and in Jesus Christ: His virgin birth, sinless life, His physical death, burial, and resurrection. We don't have to understand how these events were possible, but we do have to believe that they happened and understand that with God all things are possible (Matthew 19:26).
Knowledge of the gospel and understanding of it are two different things. Knowledge stays in the head, but understanding can lead to transformation. People can have knowledge of the gospel without putting their faith in it. This does not count toward their eternal salvation. The Ethiopian eunuch (Acts 8:26–39), Cornelius (Acts 10), Apollos (Acts 18:24–28), and the twelve men in Ephesus (Acts 19:1–7) are biblical examples of people who had personal religious history, but their salvation only came when they chose to put their faith in Christ. They had to both hear and understand the gospel.
We do not have to understand every spiritual doctrine and facet that the gospel message entails in order to be eternally saved. Even children can understand the gospel. Jesus said, "Let the little children come to me, and do not hinder them, for to such belongs the kingdom of God" (Mark 10:14). Yet at the same time, no one will ever fully understand the ways of God. We choose to believe the gospel even though there will always be facets that are a mystery to us. The basic truth of the gospel is able to be understood by anyone. We believe that if anyone is mentally incapacitated God will extend His grace to them. As we grow in our faith, we gain better knowledge and understanding on other scriptural and doctrinal topics.
Put simply, in order to go to heaven, all we have to do is this: "believe in the Lord Jesus, and you will be saved" (Acts 16:31). When we hear the gospel and understand it, we have to choose to believe it. We trust in Jesus' sacrificial death, burial, and resurrection on the third day as the one and only way for us to receive salvation. When we believe in Jesus' name, we are saved: "But to all who did receive him, who believed in his name, he gave the right to become children of God" (John 1:12). This is the simple yet profound truth of the gospel.
What is the gospel?
What is faith in Jesus? What does it mean to have faith in Jesus?
How can I make sure I'm going to heaven?
Is salvation about more than just the afterlife?
Is it possible for a person to believe in some way and yet not be saved?
Truth about Salvation