When Jesus told us to be holy, He wasn't saying to be perfect. We can't be. He was telling us to be set apart for God's purposes.

Seek first his kingdom and his righteousness, and all these things will be given to you. - Matthew 6:33

The Lord takes pleasure in those who fear Him - Psalm 147:11

If we walk in the light, as he is in the light, we have fellowship with one another. - 1 John 1:7