The passage about there being one mediator between God and man is in the context of the covenant.
But as it is, Christ has obtained a ministry which is as much more excellent than the old as the covenant he mediates is better, since it is enacted on better promises. (Hebrews 8:6)
Therefore he is the mediator of a new covenant, so that those who are called may receive the promised eternal inheritance, since a death has occurred which redeems them from the transgressions under the first covenant. (Hebrews 9:15)
…and to Jesus, the mediator of a new covenant, and to the sprinkled blood that speaks more graciously than the blood of Abel. (Hebrews 12:24)
There is one perfect mediator of a perfect covenant between God and man. Jesus Christ is the perfect mediator of a perfect covenant between God and man because Jesus Christ is both God and Man. Moses was also a mediator between God and man. Moses mediated a covenant between God and man at Mt. Sinia.
Moses goes up on the mountain and gets a message from God…
***Moses went up to the mountain of God. Then the LORD called to him from the mountain, saying: This is what you will say to the house of Jacob; tell the Israelites: ***(Exodus 19:3)
…and goes down the mountain and tells God’s message to the Israelites…
***So Moses went and summoned the elders of the people. When he set before them all that the LORD had ordered him to tell them, all the people answered together, “Everything the LORD has said, we will do.” Then Moses brought back to the LORD the response of the people. ***(Exodus 19:7-8)
…and then he goes back up the mountain a second time to give the people’s answer to God. He then gets a second message from God…
When Moses, then, had reported the response of the people to the LORD, 10the LORD said to Moses: Go to the people and have them sanctify themselves today and tomorrow. (Exodus 19:9-10)
…and so he goes down the mountain and gives Gods second message to the people.
Then Moses came down from the mountain to the people and had them sanctify themselves, and they washed their garments. (Exodus 19:14)
In Exodus 19:20, Moses goes up a third time. In Exodus 19:25, Moses goes down a third time. Moses meets God a fourth time in Exodus 20:22, and reports God’s fourth message to the people in Exodus 20:25. Moses goes up and down the mountain two additional times in Exodus 24.
Moses himself was told: Come up to the LORD (Exodus 24:1)
The LORD said to Moses: Come up to me on the mountain (Exodus 24:12)
Moses goes up and down the mountain at least six times, giving God’s messages to the people, and bringing the people’s response to God. Moses mediates a covenant between God and man, but the covenant he mediates is imperfect, becuase Moses is only a man. Moses is not God and so cannot represent God before men.
As a Roman Catholic, Jesus has brought me out of the bondage of sin and into the light of his presence, and he did it through scripture and the sacrament of confession. 33 years of habitual sin was taken away from me miraculously when I made a 37 year confession. The sin stopped cold. I know what it means to be infused with grace. I felt it on Sept 14, 2008 at 3:45 PM.
And scripture played a big part as well. Catholics read scripture in its entirety. We don’t take it one verse at a time. We try to understand every verse in its context and try to understand every verse as part of the entire Bible. Reading the Bible this way shows us clearly that the reference to Christ being the one mediator between God is in the context of the covenant, and in the context of Moses also being the mediator of a covenant between God and man.
Christ is the one perfect mediator. Only Christ can represent man before God, and only Christ can represent God before man, because only Christ is both God and man.
-Tim-