The church is always to be under the Word; she must be; we must keep her there. You must not assume that because the church started correctly, she will continue so. She did not do so in the New Testament times; she has not done so since. Without being constantly reformed by the Word the church becomes something very different.
It is grace at the beginning, and grace at the end. So that when you and I come to lie upon our death beds, the one thing that should comfort and help and strengthen us there is the thing that helped us in the beginning. Not what we have been, not what we have done, but the Grace of God in Jesus Christ our Lord.