Some people seem to have tremendous reserves of inner strength. Where do they get it? They may exhort us to look to ourselves for that power, the power of positive thinking, etc.
Real power for living, or I should say, any power for living, comes from without. It comes from God. The Bible promises, "The God of all grace . . . will Himself perfect, confirm, strengthen and establish you" (1 Peter 5:10). This is a wonderful promise. It is a part of the Good News of Jesus Christ. In other words, this is a promise directed to Christians. This is a covenant made with those receiving inner cleansing from guilt and sin through Jesus Christ. This is a pledge for those who dedicate themselves to following Christ.
Outside of Christ you must depend on your own reserves of inner strength. You can maintain this posture for a while. Don't get overconfident. Sooner or later you will come to the end of your rope. We all do. Many nervous breakdowns and panic attacks result from a failure to acknowledge this.
Turn to Christ. Receive new life from Him. Dependence upon Christ is not a sign of weakness. On the contrary, Christ is the source of life. If Christ is living in you, "Greater is He who is in you than he who is in the world" (1 John 4:4).