The converted believer is to become perfected in the love of God not just by physically obeying the Ten Commandments (which ought to be done) but also by obeying the spiritual INTENT of God's laws:
"Jesus said to him, "'You shall love the Lord your God with all your heart, with all your soul, and with all your mind.' This is the first and great commandment. And the second is like it: 'You shall love your neighbor as yourself.' On these two commandments hang all the Law and the Prophets.""
(Matthew 22:37-41, NKJV throughout)
This duality of spiritual love is signified by 8 + 8 = 16.
The 16th time the word "love" is used in 1John it says, "There is no fear in love . . ."