In About, I say the main thing is faith. Here I want to clarify faith in what. The Cross and what happened there are the most important event in history.
God chose a people at the meeting point of Asia, Africa, and Europe to be his own. Then he showed that Abraham was a fearful liar. What people has such a founder? Only God’s people. Then he showed David was an adulterous murderer. That was their greatest king. Who does that? That info certainly does not get in the official document of America’s first President, George Washington. But there it is in the story of God’s people. The OT is a path of hopelessness.
Then the Romans subdue Israel and create Pax Romana. Christians could travel the vast Roman Empire in relative ease and safety at just this time. The time was right. They also had reliable records that show that Pontius Pilate managed Judea at the time the gospels say He was crucified.
The Main Thing at the Right Time
Further, Israel, called Judah, has many people, the Pharisees, in 1 AD who not only are not falling off the edge, but are obeying every measurable command God has given. They are the first people to show clearly the other ditch.
The tax collectors and prostitutes are in one ditch. Meanwhile, the Pharisees are serious followers of God who have made it into a religion instead of a path of faith. They are in the other ditch. Both failings are mature at last, so we can see the path of faith.
So at the very right time in history, Jesus comes. In Jesus, we have one who is fully God and fully man. The third person of the deity put on human clothes and came and lived among us. This gave us a real chance to know Him. Additionally, we get to see how he dealt with people in both ditches. He also is an amazing teacher and thus gave us the New Testament. See also About Main Thing.
However, that is not the main thing for why He came. He came as knew that he, as a holy God, could not overlook any sin. It all matters to Him, so even Abraham, the founder, is lost. No one is saved.
Jesus came to die to pay for the sins against God and nullify the penalty of separation with God. God became a man, so he could die to make away for us to connect with the living God in holiness.
Jesus Dying on the Cross is the Main Thing
When sinless Jesus dies on the cross, he fulfills all the failure of the Old Testament.
As he died due to Pharisees and Romans, he showed that both non believers and believers of God were involved. We all, figuratively, held the nail to pound into Jesus hands. We cannot say we are clean.
In dying, Jesus paid for all the sins of the past and all the sins of the future in one self sacrificing act to save mankind. That is the hinge of history. Someone tried to set AD for Jesus birth, but we should set to start at the moment Jesus dies. That is the main thing.
Jesus only left us two ceremonies: baptism to show we turned to God in faith, and communion so we do not forget the main thing.
Jesus died for sinners and that includes me and all who choose to believe.
The Cross and faith in what Jesus did there is the main thing.