Christianity has its roots in the deep , firm soil of history. Jesus' incarnation- God invading human history with His presence in the form of man - is on record. Every time you write the date, you attest to the fact that God entered human history. We used to say ," in the year of our Lord" or A.D. but that has been erased from our vocabulary.
Jesus came into the world so we might know that God cares how we live, what we believe, and how we will die. Jesus came to demonstrate to us that we were made to have a personal relationship with God. He came to bridge the gap that separated us from our Creator.
" Gd was reconciling the world to Himself in Christ, not counting men's sins against them." 2 Corinthians 5:19