I was always looking outside myself for strength and confidence, but it comes from within. It is there all of the time. (Anna Freud, 20th century British psychoanalyst)
Apparently, Freud is viewing life from a purely humanist perspective. If man is merely the result of millennia of evolution, perhaps she could be right. But a Judeo-Christian perspective understands man to be the direct creation of an all-powerful God, made in God’s image. His strength and confidence ultimately come from the inner working of God in his life.
Your strength comes from God’s grace. (Hebrews 13:9)
But the Lord is faithful; he will strengthen you. (2 Thessalonians 3:3)