And may the Lord make you increase and abound in love to one another and to all, just as we do to you, 13 so that He may establish your hearts blameless in holiness before our God and Father at the coming of our Lord Jesus Christ with all His saints.—1 Thessalonians 3:12-13
The more we know God...the more we trust Him
The more we trust Him...the more we love Him
The more we love Him...the more we obey Him
Verse 10 says this:
night and day praying exceedingly that we may see your face and perfect what is lacking in your faith?
What is always lacking in our faith as fallen human beings saved by grace?
LOVE.
Beloved, true faith works through our love toward God and our love toward one another. God IS love and His love is the the bond of perfection and the overarching theme of all of Scripture. Love is the debt that is never paid and is always owed. There is always room in our hearts and our lives for more love to abound toward God and toward one another. Love enables us to fulfill the law and in so doing establishes our hearts blameless in holiness before God.
Therefore, whatever you want men to do to you, do also to them, for this is the Law and the Prophets.—Matthew 7:12
Jesus said to him, "'You shall love the LORD your God with all your heart, with all your soul, and with all your mind.' 38 This is the first and great commandment. 39 And the second is like it: You shall love your neighbor as yourself.' 40 On these two commandments hang all the Law and the Prophets."—Matthew 22:37-40
Though I speak with the tongues of men and of angels, but have not love, I have become sounding brass or a clanging cymbal. 2 And though I have the gift of prophecy, and understand all mysteries and all knowledge, and though I have all faith, so that I could remove mountains, but have not love, I am nothing. 3 And though I bestow all my goods to feed the poor, and though I give my body to be burned, but have not love, it profits me nothing.—1 Corinthians 13:1-3
Owe no one anything except to love one another, for he who loves another has fulfilled the law. 9 For the commandments, "You shall not commit adultery," "You shall not murder," "You shall not steal," "You shall not bear false witness," "You shall not covet," and if there is any other commandment, are all summed up in this saying, namely, "You shall love your neighbor as yourself." 10 Love does no harm to a neighbor; therefore love is the fulfillment of the law.—Romans 13:8-10
