How can you say that Jesus is God?

Even given the evidence for the resurrection (miracles, resurrection) many still ask: "Sure, Jesus was a great moral teacher, but could He truly be God?"

Jesus clearly claimed to be God: John 8:58 (ref. Exodus 3:14); John 10:25-38, 12:44-45; also Matthew 10:40, 28:18-19; Mark 14:60-62 (ref. Daniel 7:13-14); Luke 5:20-26, 6:5, 10:16; John 2:18-22, 5:17-23, 8:23, 13:13, 19-20, 14:6-11, 17:5; Revelation 22:12-13 (ref. Revelation 1:8). Just in John chapter 5 alone, Jesus makes six claims to equality with God: He is equal with God in his person (v. 17-18); He is equal with God in his works (v. 19-20); He is equal with God in his power and sovereignty (v. 21); He is equal with God in his judgment (v. 22, 27); He is equal with God in his honor (v. 23); and He has resurrection power (v. 25-26)!

There is much ignorance about Jesus' claim to deity (especially among Muslims). Frequently in the New Testament Jesus referred to himself as the "Son of Man." Indeed, Jesus is referred to as the "Son of Man" 88 times in the New Testament. The uninformed think this meant that Jesus was claiming to be merely a man. Quite the contrary is true. Jesus was claiming the term used by Daniel ("Son of Man" in Daniel 7:13-14) to prophecy the coming Messiah who was to have God's sovereignty, kingdom, and everlasting dominion. In his claim as a miracle worker (Matthew 11:4-6; Luke 4:18-19, 7:22-23), Jesus was referring to Old Testament prophecies from Isaiah 26:19, 29:18, 35:5-6, 61:1. The latter prophecy explicitly mentions being God's anointed one. Over 300 Old Testament prophecies speak of the coming Messiah ("Christ") and describe him as a man that stands above all other men and would have divine attributes.

The Jewish believers in Jesus used the term Messiah and Son of God interchangeably (Matthew 16:16, 26:63; Mark 1:1; Luke 4:41; John 1:49, 11:27). The Messiah is called Mighty God in Isaiah 9:6 where the context clearly describes Jesus.

That Jesus was making a claim of deity in Matthew 26:64 is even clearer as he says that he will be seen "sitting on the right hand of God and coming on the clouds of heaven." In Matthew 24:30-31 Jesus uses similar language about his Second Coming on clouds. The Jews absolutely understood that it was only God himself who came on clouds (with angels and trumpets)—often a motif in the Old Testament about God's coming in judgment against those who disobeyed. It was this claim to divinity that caused the Jewish leaders to charge Jesus with blasphemy, a crime punishable by death. See also Mark 2:1-12 and John 5:18. Other passages affirm that the Jews understood Jesus' claim to deity; see John 19:7.

But there is more. Jesus portrayed himself as God's only Son in other ways. Consider Jesus' parable of the wicked tenants of the vineyard (Mark 12:1-9). Here Jesus employs stock images and themes found in rabbinic parables: Israel as a vineyard, God as the owner, the figure of a son, etc. The parable tells us that Jesus thought of himself as God's only Son, distinct from all the prophets, God's final messenger, and even the heir of Israel itself. So this parable discloses to us that Jesus believed and taught that he was the only Son of God.

In Matthew 11:27 and Luke 10:22, Jesus states, "All things have been delivered to me by my Father; and no one knows the Son except the Father; and no one knows the Father except the Son and anyone to whom the Son chooses to reveal him." Here Jesus' self-concept as God's Son comes to explicit expression.

Incredibly, Jesus also held himself out as the arbiter of people's eternal destiny. For example, see Luke 12:8-9. Here and elsewhere Jesus claimed the authority to stand in God's place and speak to us and bring us to salvation! In John 17:3 Jesus places Himself and the Father together as the source of eternal life, affirming his own deity.

Given such claims, there are three possibilities as to his identity. Either Jesus was (a) a liar, (b) a lunatic, or (c) Lord.

If Jesus is a liar, then He has deceived more people than any other human. He could not be the greatest liar who ever lived, and also be a great moral teacher. His character is evidence of a person of absolute virtue and integrity. His instruction was pure and profound. He was not a liar.

When reading the words of Jesus, one is struck not only by His sheer intelligence but even more by his authority. O. Quentin Hyder, a practicing psychiatrist in New York City, analyzed the records of Jesus' behavior, personality and relationships for symptoms of psychiatric disorders. He said that the evidence does not support the notion that Jesus was a lunatic. Hyder concluded by saying: "A person is free to maintain that Jesus, out of honest delusion, made his claim to deity. But if one takes this position, he does so without any psychological evidence in its support and, indeed, in spite of considerable evidence to contrary."

Jesus lived a sinless, perfect life. His closest companions confirmed this (1 Peter 1:18-19, 2:21-24;  2 Corinthians 5:21; Hebrews 4:15, 7:26-27;  1 John 2:1, 3:5). Even his enemies, those who betrayed and crucified Him, acknowledged his perfect life (Matthew 27:3-4; Luke 23:14-15; John 8:46). As the most influential person who ever lived, history is measured from Jesus' life. His words, his character, and his influence all attest that Jesus was more than a mortal man.

Jesus' sinless life proves he was from God and was the Messiah as predicted in the Old Testament (Isaiah 53:9). But it is also important because it uniquely qualifies him to be our all-sufficient Savior. 

Most people readily admit to Jesus' status as a great moral teacher. We submit that it is inconsistent to admit to Jesus' stature as a great teacher and not believe what he taught. Jesus taught his own deity. He claimed to be God and proved it through his resurrection.

Scripture records that, in time, the apostles fully accepted Christ's claims of deity: Matthew 1:23 (ref. Isaiah 7:14); Matthew 17:1-9, 22:41-46, 25:31; Mark 1:2-3 (ref. Isaiah 40:3); Mark 13:31 (ref. Isaiah 40:8); Luke 2:11 (ref. Isaiah 9:6); John 1:1-4, 1:14-18, 12:41 (where John unambiguously ties Jesus to God or Yahweh of the Old Testament); John 20:24-31; Acts 2:36; Romans 9:5; Philippians 2:5-11 (also Romans 10:9-13, where Paul refers to Jesus as Lord, which in Greek is kyrios, which is the same word used for God in some versions of the Septuagint, the Greek translation of the Old Testament); Colossians 1:13-19, 2:9; 1 Timothy 3:16; Titus 2:13; Hebrews 1:2-13;  2 Peter 1:1; 1 John 5:20).

Here are passages of the Bible that directly call Jesus Christ/Yeshua Messiah "God":

A child will be born and his name is called Emanuel, God with Us. (Isaiah 7:14)

A child will be born and his name is called Mighty God, Eternal Father, Prince of Peace. (Isaiah 9:6)

The Word [Jesus] was God. (John 1:1)

My Lord and my God. (John 20:28)

Jesus existed in the form of God. (Philippians 2:6-8)

Father addresses Son as God. (Hebrews 1:8)

Jesus has all the attributes of deity, including omnipotence (Matthew 28:18), fulfilled prophecy (Luke 21:6, 7, 22, 32), omnipresence (Matthew 18:20). He did the works of deity such as creation (John 1:3), raising the dead (John 11:43-44), and is assigned power to judge the living and the dead (2 Thessalonians 1:7-8). And he was worshipped as deity (Matthew 14:33).

See also Who Is Jesus. And of course, read the four biographies of Jesus, that is, the Gospels of Matthew, Mark, Luke, and John. Decide for yourself whether Jesus really was who he claimed to be.

If Jesus was who He said He was, you and I are under judgment. If we say He was not God, we must somehow reconcile Jesus' message, the evidence, and much of history.

Historically, we can be as certain of what we read about Christ in the Bible as almost any other recorded event. Refusing to believe in Jesus is not because of a lack of evidence. Refusing to believe can only be because we thumb our nose at God, or that we are unwilling to change. People reject Jesus because of moral reasons, not intellectual ones.

Link:

Historical Jesus Outside the New Testament