What does the key of belief look like? What does it mean to believe in Jesus Christ?
In the New Testament belief in Jesus Christ is not presented as an irrational leap without content or reason—there are truths to be understood, and there is knowledge we must have. Francis Schaeffer wrote in The God Who Is There:
True Christian faith rests on content. It is not a vague thing which takes the place of real understanding, nor is it the strength of belief which is of value. The true basis for faith is not the faith itself, but the work which Christ finished on the cross. My believing is not the basis for being saved—the basis is the work of Christ. Christian faith is turned outward to an objective person: “Believe on the Lord Jesus, and thou shalt be saved.”
In other words, I don’t have faith in my faith, I have faith in Jesus Christ.
And who is Jesus Christ? The New Testament gives us the knowledge we need about who Jesus Christ is and about His death and resurrection.
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. Then he appeared to more than five hundred brothers at one time, most of whom are still alive, though some have fallen asleep. Then he appeared to James, then to all the apostles. Last of all, as to one untimely born, he appeared also to me.
1 Corinthians 15:3-8 (ESV)
Having knowledge about the person and work of Jesus Christ is necessary to believe in Him, but those who have only knowledge, even if they believe those facts to be true, believe only in knowledge. They do not believe in Jesus Christ. James is clear about this when he states that even demons believe God is one.
You believe that God is one; you do well. Even the demons believe—and shudder!
James 2:19 (ESV)
The New Testament teaches that Christians don’t merely know facts, they confess Jesus as Lord. Christian belief is presented as believing into Jesus. We believe in Jesus. We believe on the Lord Jesus.
The Greek word that is translated to believe or belief is also translated as faith. Two different words are used in English, but there is only one basic word in Greek. It comes from a word that means to convince or to persuade. W. E. Vine defines to believe:
PISTEUŌ (πιστεύω), to believe, also to be persuaded of, and hence, to place confidence in, to trust, signifies, in this sense of the word, reliance upon, not mere credence.
Christians have understood and acknowledged the reality that before God we stood guilty of sin before Him and under His judgment. We have realized our inability to ever make ourselves right before Him. In repentance we have had, as Vine writes, a “change of mind [that] involves both a turning from sin and a turning to God.” We have believed in Jesus as we acknowledged Him as Lord, having confidence that His death for our sins satisfied the judgment of God we deserved and turning to follow Him in obedience. We have placed our confidence, our trust, our reliance on Him. We have believed in Him.
…if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved. For with the heart one believes and is justified, and with the mouth one confesses and is saved.
Romans 10:9b-10 (ESV)
Confess is a rich word. To confess is not only to speak, but to agree. Acknowledge is a synonym of confess. We usually think of confess in the context of confessing when we’ve done something wrong, but here the context is confessing that Jesus is Lord. A. T. Robertson writes regarding confessing Jesus is Kurios, the Greek word for Lord:
No Jew would do this who had not really trusted Christ, for Kurios in the LXX [the Septuagint, a Greek translation of the Old Testament] is used of God. No Gentile would do it who had not ceased worshiping the emperor as Kurios. The word Kurios was and is the touchstone of faith.
A Christian believes God raised Jesus from the dead. Jesus
…was declared the Son of God with power by the resurrection from the dead, according to the Spirit of holiness, Jesus Christ our Lord
Sometimes when a person hears about who Jesus is and what it means to be a Christian, belief in Jesus Christ is instantaneous. Sometimes a person has knowledge about Jesus for a time before he comes to belief. But knowledge alone does not make a person a Christian, nor does it save someone from the just wrath of a righteous God. Remember, the words of Paul to the jailer at Philippi were:
Believe in the Lord Jesus, and you will be saved
Key: Glasgow Locksmiths
Francis Schaeffer, The God Who Is There, Inter-Varsity Press, 1968, p. 133.
W. E. Vine, Old Testament Edited by F. F. Bruce, Vine’s Expository Dictionary of Old
and New Testament Words, 1981; Believe: Vol. 1, p. 116, Repentance: Vol. 3,
The Complete Word Study Dictionary: New Testament, compiled and edited by Spiros
Zodhiates, 1992, p. 1133.
A. T. Robertson, Word Pictures in the New Testament, 1931, Vol. IV, p. 389.