This is often used when a person tries to put to death his sinful desires without help from God; he tries to stop sinning only with the help of his own strong will. Some people may manage this to some degree, but in the end it is impossible to fully overcome sin in one’s own strength - after a time they will come to an end of their own strength, of their own strong will. A Christian needs the strength and help of the Holy Spirit to completely overcome sin. A common reason that people get discouraged is because they still trust in their own strength, and don’t put all their trust in God. (2 Corinthians 12:7-10; Psalm 147:10-11; Zechariah 4:6.)