How do we know God's covenant with His people is secure?

In Exodus 19:5-6, God calls Israel to be a peculiar treasure to Him, establishing a covenant based on their obedience to Him. This covenant, however, is ultimately anchored in the work of Christ, who fulfilled the law and paid the penalty for sin through His sacrificial death. Our assurance comes from recognizing that while our obedience is imperfect, Christ's righteousness secures our status before God. Hebrews 10:14 emphasizes that by a single offering, Christ has perfected for all time those who are being sanctified. Thus, our security in the covenant rests in Christ's finished work, not our own efforts.