There is no one else that can mediate with God for us. If Jesus is the ONLY mediator, that indicates Mary and saints cannot be mediators. They cannot mediate our prayer requests to God.
Further, the Bible tells us that Jesus Christ Himself is interceding for us before the Father, "Therefore He is able to save completely those who come to God through Him, because He always lives to intercede for them" (Hebrews 7:25). With Jesus Himself interceding for us, why would we need Mary or the saints to intercede for us?
Who would God listen to more closely than His Son? Romans 8:26-27 describes the Holy Spirit interceding for us. With the 2nd and 3rd members of the Trinity already interceding for us before the Father in Heaven, what possible need could there be to have Mary or the saints interceding for us?
In describing how we should pray, Jesus gave us the template of the "Our Father".
Matt 6:7"And when you pray, do not heap up empty phrases as the Gentiles do, for they think that they will be heard for their many words. 8Do not be like them, for your Father knows what you need before you ask him. 9 Pray then like this: "Our Father in heaven, hallowed be your name. 10 Your kingdom come, your will be done,....
So, you are saying that you can insert yourself between God and me? You are the arbiter of how He loves me, and how I love Him? You get to tell me when God will be pleased, and when He will not?
Baloney!
I have sincerely questioned why anyone would even imagine going to anyone other than the Christ....since He is in control of it all. In a real sense by doing so it would appear the individual "needs" more than Christ has to offer, which then dethrones Him from His rightful place.
Wow! Who KNEW? Is that in the BIBLE? REALLY?
Well, the jig is up then, isn't it.
Look, excuse the silliness. But isn't it silly to think that we don't know about this verse?
I don't know about you, but I managed to escape from high school 45 years ago. About halfway through my freshman year I realized that argument was better suited as a tool for friends to examine the truth in love than as a weapon with which to triumph over trumped up adversaries.
This particular verse and the argument which depends on it has been made at least dozens of times. And yet I still pray to Mary, Dominic, Terese, Katherine Laboure, and more. Read the preceding 5 verses and you'll get a hint as to why the argument is not persuasive.