Jesus always was and always will be God the Son (The second person of the Trinity). When he was born from a human mother he was God (incarnation), when he died on the cross he was God and - most importantly - after he resurrected from the dead he was God. John 1:1 tells us that 'In the beginning was the Word, and the Word was with God and the Word was God. Then in verse 14 we read that 'the word became flesh and dwelt among us'. What follows are several examples from scripture that which lead us to believe that Jesus is the Son of God.
For starters, the Greek word theos (God) in the New Testament usually refers to God the Father. However, there are a few places where the oldest and better manuscripts use the word theos in reference to God the Son (Jesus). These include John 1:1; 1:18; 20:28; Romans 9:5; Titus 2:13; Hebrews 1:8; and 2 Peter 1:1.
The Greek word kyrios (Lord) is used in the Greek translation of the Old Testament (Septuagint) as a translation of the word yhwh (Also seen as 'Yahweh', 'The Lord', and 'Jehovah'). It does this 6,814 times in total. So it is safe to say that any Greek speaking Jew during the time of the New Testament would recognize in context, that the word kyrios was referring to the creator of heaven and earth (Genesis 1:1); the one who had brought them up out of Egypt (Leviticus 11:45).
In addition to these Old Testament scriptures, many places in the New Testament use the word 'Lord' (kyrios) to refer to Christ in contexts which can only be understood if we call him Yahweh or God himself. Some of these include Matthew 3:3; 22:44; Luke 1:43; 2:11; 1 Corinthians 8:6; Hebrews 1:10-12; Revelation 19:16.
With this information we can see clearly that Jesus was no ordinary man who walked the earth. He is God in flesh, who in his authority said in John 3:36, "everyone that believes in the Son has eternal life; whoever does not obey the Son shall not see life, but the wrath of God remains on him." What is it that we are to obey? The call to believe (John 3:16), worship (Philippians 2:9-11), and follow him (John 10:27; 12:26).