Many people believe in Jesus. They will acknowledge that some man in Judah lived and died during the first century CE Notice that they call the first century the common era because they don’t believe Jesus to be the Lord – that is God. AD stands for anno Domini, Latin for year of the Lord.
The first chapter of Mark should quell any doubts about who Jesus really is. Mark say in the very first verse that Jesus is the Messiah, the Son of God. He goes on to prove this in his Gospel. Mark quotes from Isiah to establish John the Baptist’s credentials as a prophet who was to prepare the way for Jesus. John says that Jesus will baptize in the Holy Spirit. This is something that only God can do. No one else can cause a person to be baptized – immersed – in the Holy Spirit. That is a function of God alone.
At Jesus’ baptism, we have the description of Jesus being part of the Trinity of God as all three are manifested together to announce that Jesus is the Son. The Spirit descended and the Father announced that Jesus is the Son. You won’t see this happening to any of even the best Bible teachers, gurus, or “holy” men of any religion.
Next, we see that Jesus is completely sin free. He lets Satan tempt him but doesn’t sin in any way. Though Mark doesn’t mention it, it is clear in Matthew’s and Luke’s Gospels. Only the perfect, holy, Son of God could endure this direct onslaught of Satan’s attack without sin. Only God is Holy and this also shows that Jesus is God.
Jesus begins his ministry by preaching repentance – the continuation of the message that John announced. He tells people to repent and believe the good news. That may not seem like much of a proof that Jesus is more than a teacher, but it is evident that power and authority accompanied his teaching. When he called his first disciples, they were willing to leave their livelihood and follow him. He told them that they would become fishers of men. The good news that Jesus preached changes lives and captures people for the kingdom of God.
Jesus’ authority as the Son of God is evident when he cast a demon out of a man with an unclean spirit. The demon knew that Jesus is the Messiah, the Holy One of God. While people today will not recognize this, the spiritual realm has no doubts about who Jesus is. The demonic forces blind us to who Jesus is to keep us from seeing the truth of the gospel (2 Cor 4:4).
When we believe by grace through faith that Jesus is who Mark says, the Son of God, then we will be saved. Until then, believing that Jesus was a good guy or even just trying to follow his good teaching will not save anyone.