What does the Bible say about trusting in self versus Christ?

Throughout the scriptures, particularly in 1 Samuel 31, we see the illustration of Saul as a representation of the sinful nature in all mankind, who seeks to exalt self above God. This self-exaltation is depicted in the choice of Saul as king, despite God's warning through Samuel. Jeremiah 17:5 emphasizes, 'Cursed is the man who trusts in man and makes flesh his strength.' In contrast, true salvation and trust must be placed solely in Christ, who is our righteousness and holiness. Romans 10:9 states that if we confess with our mouth the Lord Jesus and believe in our heart that God raised Him from the dead, we shall be saved. This emphasizes that reliance on self or works leads to spiritual death, while faith in Christ leads to eternal life.