Matthew 22:37-39, HCSB
So often, we fall into a routine of attempting to improve ourselves from the outside in by attempting to discipline ourselves to do things we do not want to do. True change starts from the inside, through the empowering of the Holy Spirit dwelling in us, and works it way out into our behavior.
We can not obey the two commandments quoted above in our own strength, but we can walk more closely with the Lord, day by day, when we rely on the Holy Spirit to develop in us a genuine love for God and His Word, which then demonstrates itself in our attitudes and behavior toward others.