God's covenant is sure because it is established by His eternal purpose and fulfilled by Christ's work.
The assurance of God's covenant arises from its foundation in His sovereign will, as stated in 2 Samuel 23:5, which affirms that God has made an everlasting covenant that is ordered in all things and sure. This covenant is anchored in the redemptive work of Christ, our surety, who accomplished our salvation on the cross. God’s promises are unbreakable because they are not contingent upon human actions but are fulfilled in the perfect obedience and sacrifice of Jesus. In this way, the believer can rest in the assurance that God's plans will not fail and that all blessings of salvation are guaranteed to His chosen people through Christ.
Scripture References:
2 Samuel 23:5, Isaiah 54:10, Romans 8:30
Commentary