Christ, What role does He play?

Christ, what role does he play in my life? I am human and prone to err. I am and shall be held accountable for my mistakes, both in the here and now and in the hereafter. And I have nothing that can appease a just and holy God. Therefore I need Christ to defend me and atone for my failures. He alone was sinless and worthy in the eyes of God. And what does He expect in return from me? He expects that I amend my ways and follow Him as much as it is humanly possible. He provides no free ride or an easy road but at times a cross. No one can serve two masters in this world.