Answer
We must keep in mind that the Bible is intended to be taken as a whole. The books preceding the Four Gospels are anticipatory, and the books that follow are explanatory. Throughout the whole Bible, what God requires is faith (Genesis 15:6; Psalm 2:12; Habakkuk 2:4; Matthew 9:28; John 20:27; Ephesians 2:8; Hebrews 10:39). Salvation comes not by our own works but by trusting what God does on our behalf.
Each of the Gospels has its own emphasis on the ministry of Christ. Matthew, writing to a Jewish audience, emphasizes Jesus’ fulfillment of Old Testament prophecy, proving that He is the long-awaited Messiah. Mark writes a fast-paced, condensed account, recording Jesus’ miraculous deeds and not recording His long discourses. Luke portrays Jesus as the remedy of the world’s ills, emphasizing His perfect humanity and humane concern for the weak, the suffering, and the outcast. John emphasizes Jesus’ deity by selecting many conversations and sayings of Jesus on the subject and also including "signs" that prove He is the Son of God.
The Four Gospels work together to provide a complete testimony of Jesus, a beautiful portrait of the God-Man. Although the Gospels differ slightly in theme, the central Subject is the same. All present Jesus as the One who died to save sinners. All record His resurrection. Whether the writers presented Jesus as the King, the Servant, the Son of Man, or the Son of God, they had the common goal that people believe in Him.
We’ll delve into the theology of the Gospels now. John includes many statements of faith and commands to believe. These inclusions fit his stated purpose, "that you might believe that Jesus is the Christ, the Son of God; and that believing you might have life through His name" (John 20:31). The other Gospels (the Synoptics) are no less concerned that we trust in Christ. Their appeals to faith are less overt but are just as genuine.
Jesus proclaims the need for righteousness, and He warns of the penalty of sin, which is hell. However, Jesus always presents God as the standard of righteousness and Himself as the means of righteousness. Without Christ, righteousness is unattainable and hell is inevitable. The Sermon on the Mount (Matthew 5—7) is a case in point:
- Jesus begins the Sermon on the Mount with a description of the blessed life (Matthew 5:1–12). The Beatitudes are not telling us "how to" be righteous, but are simply describing righteousness.
- He presents Himself as the fulfillment of the Old Testament law (Matthew 5:17–18). This is a key verse because, to earn our own righteousness, we must fulfill the law; here, Jesus says that He will do it for us.
- He says that no amount of our own good works will gain us entrance to heaven (Matthew 5:20). This is another important statement in the sermon. The Pharisees were the most religious people of the day, but Jesus says even they are not good enough to enter heaven. Jesus will go on to say that it’s not a religious system that saves, but He Himself.
- He deepens the understanding of righteousness and defines it according to God’s standard, instead of man’s interpretation of the law (Matthew 5:21–48). He explains God’s intent behind several Old Testament laws. The standard is so high as to make everyone, even the most dedicated religious practitioner, guilty before God.
- He describes three popular religious activities—almsgiving, prayer, and fasting—as hypocritical when practiced by the outwardly religious (Matthew 6:1–18). Jesus’ focus, as with the laws He just mentioned, is the heart condition of man, not the works we can see.
- He warns that there will be "many" in the day of judgment who will have performed great works for God yet will be turned away from heaven (Matthew 7:21–23). The reason given is that Jesus never "knew" them. There was no familial relationship, only "good" works, which is not enough.
- Jesus concludes the Sermon on the Mount with the audacious statement that He alone is the foundation for building one’s religious life (Matthew 7:24–27). It is an appeal to trust "these sayings of Mine" enough to abandon all other foundations.
To summarize, in the Sermon on the Mount Jesus meticulously deconstructs the pharisaical religion of good works, points to a holiness greater than our own, and offers Himself as the sole basis of religion. Accepting what Jesus says in this sermon requires faith in His Person.
Matthew’s Gospel goes on to emphasize faith in at least the following verses: Matthew 8:10, 13, 26; 9:2, 22, 28-29; 12:21; 13:58; 14:31; 15:28; 16:8; 17:17; and 18:6. Also, Matthew includes a very clear presentation of Jesus as the Son of God in this exchange: "He said to them, ‘But who do you say that I am?’ Simon Peter answered and said, ‘You are the Christ, the Son of the living God.’ Jesus answered and said to him, ‘Blessed are you, Simon Bar-Jonah, for flesh and blood has not revealed this to you, but My Father who is in heaven’" (Matthew 16:15-17).
Mark’s Gospel contains at least the following references to faith in Christ: Mark 1:15; 2:5; 4:40; 5:34, 36; 6:6; 9:19, 23, 42; 10:52; 11:23; and 16:14. In Luke’s Gospel we see at least these verses promoting faith in Christ: Luke 5:20; 7:9, 50; 8:12, 25, 48, 50; 9:41; 12:28, 46; 17:19; 18:8, 42; and 24:25. As we continue to see Scripture as a unified whole, we will see that there is only one message of salvation, and the Four Gospels provide the basis for that message.
The Epistles, which follow the Gospels, elaborate upon the same theme: salvation by faith in Christ. The overarching theme of Romans is the righteousness that comes through God and the doctrine of justification by grace through faith. The central theme of Galatians and Colossians is the same. The book of Hebrews stresses the pre-eminence and perfection of Christ, the “author and perfecter of our faith” (Hebrews 12:2). First and Second Corinthians, Ephesians, Philippians, 1 and 2 Thessalonians, the pastoral epistles of Timothy and Titus, Philemon, James, 1 and 2 Peter, all describe the holy living, both personally and corporately within the church, and the hope for the future that should be the natural result of life in Christ. The three epistles of John reiterate the basics of the faith and warn against those who would call them into question, also the main theme of Jude. Revelation, the final book of the New Testament, presents the last act of God’s plan for mankind and the fate of those who hold onto the same faith expounded in the entirety of the New Testament—faith in Christ alone.