How do we know God's covenant of salvation is true?

The assurance of God's covenant comes from the promise and fulfillment found in Jesus Christ. God the Father made a covenant with the Son, guaranteeing the salvation of His chosen people, as evidenced in Galatians 4:4-5, where it states that Jesus was sent 'to redeem them that were under the law.' Therefore, the covenant's truth is grounded in Christ's obedience and atoning sacrifice, securing the place of His people in the kingdom. This fulfillment demonstrates that salvation is not contingent upon our actions, but rather on the accomplished work of Christ.