“Then they said to Moses, ‘You speak with us, and we will hear; but let not God speak with us, lest we die.’”Exodus 20:19
Israel had been complaining against the Lord’s leading ever since Moses began the process of confronting Pharaoh to let Israel go (Exodus 5:21). In chapters 16 and 17 their complaining was over food and water yet the Lord provided their need. The people knew they had sinned so they “stood afar off” (v 18) fearing His wrath and in awe of the physical manifestations expressing His special presence. They could not approach God in their sinful state. They needed a mediator, one who could converse with God on their behalf.
They had witnessed occasions where God had already spoken to them through Moses and Moses had spoken to God and been answered. God had already made Moses their mediator. We sinners all need a mediator to speak on our behalf to a holy God. In grace God promised just such a Person: “And the Lord said to me: ‘What they have spoken is good. I will raise up for them a Prophet like you from among their brethren, and will put My words in His mouth, and He shall speak to them all that I command Him’” (Deuteronomy 18:18).
Paul recognised this Mediator as being Jesus. He wrote, “For this is good and acceptable in the sight of God our Saviour who desires all men to be saved and to come to the knowledge of the truth. For there is one God and one Mediator between God and men, the Man Christ Jesus, who gave Himself a ransom for all, to be testified in due time” (1 Timothy 2:3-6). Being both God and Man Jesus alone is able to mediate between sinful man and holy God. He is qualified to do so because He is without sin and “gave Himself a ransom for all” (Romans 5:8; 2 Corinthians 5:21).
The writer of Hebrews also recognized Jesus as the fulfillment of the promise for the Prophet who would mediate between God and man forever: “But now He has obtained a more excellent ministry, inasmuch as He is also Mediator of a better covenant, which was established on better promises” (Hebrews 8:6). The covenant God made with Israel through Moses was meant to show Israel’s and our sinfulness but it could not save from that sin. The New Covenant is better in that it is based on the unconditional covenant God made with Abraham and it can save from sin because in it God changes the heart.