So you define repentance as "completely stop sinning" and anything less is not repentance? Are you sinless, without fault or defect, flawless, 100% of the time, just like God the Father? Again, the Greek word for "repent" is "metanoia" (noun) and "matanoeo" (verb) you see as defined in the Strongs #3340, 3341: to think differently or afterwards, reconsider. After thought, change of mind. Not sinless perfection. When God tells an unsaved man to repent, He means for that man to change his mind about how to reach God and accept His way of salvation. The person must change his mind from any idea of saving himself through religion or good works, and trust Christ’s finished work of redemption as the all sufficient means of their salvation. Trust exclusively (faith) in Christ for salvation.
Christ sets up the high ideal of perfect love, not that we will attain it in this life, however, that is God's high standard. God cannot compromise His standard. The word perfect comes from teleios, end, goal, limit. Here it is the goal set before us, the absolute standard of our Heavenly Father. The word is used also for relative perfection as of adults compared with children.