Buried with him in baptism, wherein also ye are risen with him through the faith of the operation of God, who hath raised him from the dead. We must have faith in the operation of God. God did an invisible operation on us when we were baptized. We were put into Jesus when Baptized and got redemption. Its free because all we do is believe it happened.
Romans explains that the old testament made man work for righteousness.
Professing themselves to be wise, they became fools, And changed the glory of the uncorruptible God into an image made like to corruptible man, and to birds, and fourfooted beasts, and creeping things. Who changed the truth of God into a lie, and worshipped and served the creature more than the Creator, who is blessed for ever. For there is no respect of persons with God. But there rose up certain of the sect of the Pharisees which believed, saying, That it was needful to circumcise them, and to command them to keep the law of Moses. He did it to show man that man can't make himself good.