Hebrews 13:21

make you perfect Not the verb so often used to express "perfecting" but another verb "may He fit" or "stablish" or "equip you."

to do his will, working in you … In the Greek there is a play on the words "to doHis will, doingin you." There is a similar play on words in Philippians 2:13.

to whom be glory for ever and ever Lit. "to whom be the glory (which is His of right) unto the ages of the ages." The same formula occurs in Gal 1:5; 2 Timothy 4:18. The doxology may be addressed to Christ as in 2 Peter 3:18.