As taught in 2 Timothy 2:20–21, what is required of us in order to be truly useful to God and his work? 3. Hebrews 12:10 reads, "God disciplines us for our good, that we may share in his holiness." Why do you think God must discipline you in order for you to share in his holiness? 4. Read Hebrews 12:14. Why are we told to make every effort to be holy?