He is a God, meant to be in a place called heaven where there are no suffering and life is so good. But because of our Father's love, He gave His Son, Jesus, so we can realign our relationship to Him and make His love experienced by everyone. Jesus lived humbly on earth as He was sent here for that purpose. That is why Jesus' birth is a signaling of love to the world.
I think believing God said
Could make the society
*Won't kill each other
*Must be good
*Do not make Adultery
In John 10:30, Jesus said "I and the father are one"
He is God. He is free of sin
If Jesus is God then Mary is the mother of Jesus, then Mary is the mother of God
Because she is conceived free of sin
She heartily said in Luke 1:38 "I am the handmaid of the Lord, be it done to me according to your word".
Because she is conceived by the holy spirit
This is according to the Catholic doctrine called the "Assumption"
Christ was crucified for the salvation of all men
It is indeed offered to all yet few people follow him (Luke 9:23)