F.Y.I. The Catholic Church does not view Mary as a mediator. That role is for Jesus alone. All the saints in heaven, as well as living Christians, act as intercessors for one another. I think where you error, is beleiving Intercession and mediation are the same, but they are not, they are entirely two different things.
Lets take a look at what the Catechism of the Catholic Church has to say about it.
970:
"Mary’s function as mother of men in no way obscures or diminishes this unique mediation of Christ, but rather shows its power. (pay close attention here Mec99) But the Blessed Virgin’s salutary influence on men... flows forth from the superabundance of the merits of Christ, rests on his mediation, depends entirely on it, and draws all its power from it."[SUP] "No creature could ever be counted along with the Incarnate Word and Redeemer; but just as the priesthood of Christ is shared in various ways both by his ministers and the faithful, and as the one goodness of God is radiated in different ways among his creatures, so also the unique mediation of the Redeemer does not exclude but rather gives rise to a manifold cooperation which is but a sharing in this one source.""
Did you catch that Mec99? I think it's worth repeating.... "But the Blessed Virgin’s salutary influence on men... flows forth from the superabundance of the merits of Christ, rests on HIS mediation, depends entirely on it, and draws all its power from it."
Now concerning 1Tim.2:5, many think that the practice of praying to the saints goes against the Bible, claiming that Catholics are making them mediators between God and man and thus diminishing Jesus‘ role as the sole mediator.But this is not an appropriate interpretation of the passage. Let‘s see why not…In the O.T. we see that Moses, Abraham, and Job interceded on behalf of others… that’s mediating between God and man. We know that it is okay to ask others here on earth to pray and intercede for us…. that’s mediating between God and man. So we have a situation here where a passage of the Bible is being misinterpreted and misunderstood.
There is only one mediator between God and man, the man Jesus Christ, but as members of the Body of Christ, He allows us to share in His mediation.
Also, Scripture tells us that we have only one foundation, Jesus Christ (1 Cor 3:11); but, Scripture tells us that there is more than one foundation (Eph 2:19-20). Scripture tells us that we have only Lord, Jesus Christ (Eph 4:4-5); but, Scripture tells us there is more than one lord (Rev 19:16). Scripture tells us that we have only one Judge, Jesus Christ (James 4:12); but, Scripture tells us there is more than one judge (1 Cor 6:2).
These are not contradictions in Scripture, not when these passages are all properly understood in context. Jesus is the only foundation; Jesus is the only Lord; and Jesus is the only Judge. But, we are members of Jesus‘ Body. Therefore, we are able, according to the graces given by Christ, to share in Jesus‘ role as foundation, as lord, and as judge, and in other aspects of Christ, as well. Another example, a father shares in God‘s role as Father, by His grace. And, so also, we, and the saints in Heaven, and the angels in Heaven, can share in Christ‘s role as Mediator.---www.catholicscomehome.org