that you may walk worthy of the Lord, fully pleasing [Him,] being fruitful in every good work and increasing in the knowledge of God. Colossians 1:10 (NKJV)
First God saved us and made us worthy in His own power. We are already worthy apart from anything we have done in His sight.
Now He desires us to see ourselves and act as His worthy ones. This is what it means to walk worthy of the Lord.
He has made us righteous by He himself becoming our Righteousness. He now wants us to think, behave and live as the righteous ones we already are in Him. He has made us holy, He Himself being our Holiness. Now He desires us to live and walk as His holy ones.
A walk worthy of the Lord is living and conducting ourselves on the outside what God has made us to be on the inside.
This starts by knowing it, believing it, being persuaded of it then consequently effortlessly acting on it.