There is a lot of talk right now, good talk, making sure that Christians understand that one never moves beyond the gospel after conversion. Princeton theologian B.B. Warfield once wrote a wonderfully clear statement on the centrality of the gospel for all of life:
There is nothing in us or done by us, at any stage of our earthly development, because of which we are acceptable to God. We must always be accepted for Christ’s sake, or we cannot ever be accepted at all…This is not true of us only when we believe. It is just as true after we have believed. It will continue to be true as long as we live. Our need of Christ does not cease with our believing; nor does the nature of our relation to Him or to God through Him ever alter, no matter what our attainments in Christian graces or our achievements in behavior may be. It is always on His “blood and righteousness” alone that we can rest.
“Miserable-Sinner Christianity in the Hands of the Rationalists”, The Works of Benjamin B. Warfield, vol. 7, 113ff.