He makes the righteous (the justified ones) perfect (complete). This means we are all in progress. This means that justification is only the beginning; there is a process to following this man Jesus. He has called us, not just to follow Him but to be like Him. He calls us to a life of holiness. He calls us out of ourselves into Himself. He is making somebodies out of nobodies. He is making the clumsy into the skilled. He sanctifies the justified. We are all in that process. He has enrolled us in heaven to include us in the great assembly of the completed.
“But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to innumerable angels in festal gathering, and to the assembly of the firstborn who are enrolled in heaven, and to God, the judge of all, and to the spirits of the righteous made perfect, and to Jesus, the mediator of a new covenant, and to the sprinkled blood that speaks a better word than the blood of Abel. (Hebrews 12:22–24 ESV)
{From “Sonlight for the Soul”, by H. Lamar Smith)