How do we know the sufficiency of Christ for salvation is true?

The sufficiency of Christ is the foundation of our faith, asserting that Jesus' sacrifice was entirely sufficient for the salvation of the elect. In Romans 3:24-26, Paul speaks of being justified freely by God's grace through the redemption that is in Christ Jesus. Since Christ perfectly fulfilled God's law and bore the sins of His people on the cross, we believe that salvation is entirely of the Lord, and our works do not contribute to our justification. This understanding reflects the historic Reformed view that emphasizes grace alone (Sola Gratia) and faith alone (Sola Fide).