Christianity is between God and man, but God must always be the main focus because He is eternal and we are limited. We cannot live for ourselves neither can we leave for Men.
God exist for himself and Man exist to give God glory. If anything we do is done away from God’s plan, we are declaring sufficiency in ourselves instead of being dependent on the creator.
Our giving, our honour, our love is reciprocal; God is the one that First gave and everything we do is all replicating the goodness he first showed to us.