From Martin Lloyd-Jones book, The church and the Last Things:
“There is a danger, I sometimes think, that in our emphasis upon justification by faith only, we fall into the error of forgetting this further differentiation on the basis of our works, of our faithfulness as Christian people. We have to fight for the great doctrine of justification by faith, it is constantly being attacked, but it would be a very grievous thing if, in asserting that, we in any way detracted from this other teaching which reminds Christian people that all their works are observed by the Lord, the righteous judge, and that what you and I do as Christians in this world will have an effect upon our life in glory in the next world.”
What he means by this is that we will still be judged for our works, even though we have been fully justified before the Father. How we live as believers according to His word, still matters. We are to be more conformed by His word, yielding more and more to it.