The truth recorded by Matthew 28 is repeated in various ways throughout the New Testament. Consider the Book of Hebrews, one of our main sources of information about the difference between the Old and New Covenants. The writer of Hebrews begins by stating his theme in one sentence:
Long ago, at many times and in many ways, God spoke to our fathers by the prophets, but in these last days he has spoken to us by His Son, whom He appointed the heir of all things, through Whom also He created the world. (Hebrews 1:1-2)
Here is a contrast with three parts:
Time
“Long ago” / “In these last days
Those to Whom God Spoke
“To our fathers” / “To us”
How God Spoke
“By the prophets” / “By His Son”
This contrast shows that there are two distinct ways in which God has dealt with people. We are not in the first group, but in the second. We have not been left without a voice from heaven. Just the opposite is true. We now have the clearest voice of all. Jesus Christ is “the radiance of the glory of God and the exact imprint of His nature” (Hebrews 1:3), for He Himself is truly God (Hebrews 1:8). When God spoke beforehand through prophets and angels His word was to be carefully followed. Hebrews makes the point that we must pay even closer attention to God’s own Son.
Pay much closer attention! How shall we escape?
Therefore we must pay much closer attention to what we have heard, lest we drift away from it. For since the message declared by angels proved to be reliable, and every transgression or disobedience received a just retribution, how shall we escape if we neglect such a great salvation? It was declared at first by the Lord, and it was attested to us by those who heard. (Hebrews 2:1-3)