To be holy is to live in the spirit and not in the flesh. Everything about us must be holy. Our thoughts Philippians 4:8 and our speech Psalm 141:3. For us to be holy we must model Jesus.
The only way I can stand blameless before God is to repent. We all have sinned and sin is what spots us and makes us have blame. The only way our sins are washed away is by repenting. For we have all come short of the glory of God (Rom 3:22-24), but every time he forgives us he forgets.