How do we know the sufficiency of Christ's work for salvation?

The sufficiency of Christ’s work is rooted in His perfect life, sacrificial death, and glorious resurrection, which collectively provide everything required for our justification and redemption. In Colossians 1:22, it is declared that through His body of flesh, Christ presents us holy, unblameable, and unreprovable in God’s sight. This means that in Christ, we are sufficed for reception before God. Additionally, the fruits of His work—such as justification and sanctification—are revealed through the Word of God, which assures believers that they are secured in Him. As all who are called are given faith to believe, they realize therefore that nothing in themselves is sufficient, but all sufficiency is found in Christ alone.