Then Moses went up to God, and the Lord called to him from the mountain and said, “This is what you are to say to the descendants of Jacob and what you are to tell the people of Israel: ‘You yourselves have seen what I did to Egypt, and how I carried you on eagles’ wings and brought you to myself. Now if you obey me fully and keep my covenant, then out of all nations you will be my treasured possession. Although the whole earth is mine, you will be for me a kingdom of priests and a holy nation.’ These are the words you are to speak to the Israelites.”
This is God’s preface to the covenant he was about to make with the people at Sinai, which is variously referred to as the Sinaitic Covenant, the Mosaic Covenant, or the Law. First, God reminds the people that he delivered them from Egypt through the majestic imagery of carrying them “on eagles’ wings.” Then, he provides a conditional, if-then promise: “If you obey me fully and keep my covenant, then out of all nations you will be my treasured possession…[and] a kingdom of priests and a holy nation.” The promise is preceded by and predicated upon remembrance of God’s faithfulness, and the promise is conditioned on Israel’s continuing faithfulness.
In Christ, we have a different sort of promise. We are empowered to live under an unconditional “law” called grace, expressly because Jesus has met the condition of the former law. God sent Jesus “in order that the righteous requirement of the law might be fully met in us…” (Romans 8:4).
For us, through Jesus’ righteousness and faithfulness in living out the Sinaitic Covenant, we have a promise that is unconditional. Peter parallels the above Exodus verse for emphasis:
But you are a chosen people, a royal priesthood, a holy nation, God’s special possession, that you may declare the praises of him who called you out of darkness into his wonderful light. Once you were not a people, but now you are the people of God; once you had not received mercy, but now you have received mercy.
–1 Peter 2:9-10
Thanks be to God through Jesus Christ our Lord!