Got this illustration when trying to explain God’s promises at Church this morning.
When someone issues a check, he puts his signature on it. Otherwise, that check would not work. Similarly, God has given us a check of His promises, and has put the Name of Jesus Christ as the signature on it. In Christ’s Name we have received all the promises in truth. Therefore, the Bible says:
For no matter how many promises God has made, they are "Yes" in Christ. And so through him the "Amen" is spoken by us to the glory of God. (2Cor. 1:20)
Have you got the signature of Christ on your check?