'Practicing' in the Bible

Now in that city there was a man named Simon. He was practicing occult arts and thrilling the people of Samaria, claiming to be someone great.

Likewise, keep practicing these things: what you have learned, received, heard, and seen in me. Then the God of peace will be with you.

If we claim that we have fellowship with him but keep living in darkness, we are lying and not practicing the truth.