The pivotal point in history
Jesus was crucified on the cross with two criminals, one on each side. One repented and was told that on that day he would be in paradise with Him. The old covenant had been superseded by the new and the proof was in the resurrection.
Christianity as we know it would not have existed without the resurrection and today we would be following the teaching of another popular Rabbi and his words would have joined the countless words of other religious obedience.
The resurrection of Christ changed everything and we follow His teaching not to be saved, but because we are already saved. Christians have discovered what it means to discover Him and personally know Him.