My own strength

This refers to a person who is attempting to put to death their sinful desires without help from God; not sinning by sheer strength of will. Some people may manage this to some degree, but ultimately it is impossible to come to total victory in one’s own strength, eventually one will come to an end of their own strength. A Christian needs the strength and guidance of the Holy Spirit to completely conquer sin. A common reason for discouragement is basing your faith on past experiences of defeat; i.e. basing it on reliance on your own strength, rather than on God. (2 Corinthians 12:7-10; Psalm 147:10-11; Zechariah 4:6)