5."For there is one God, and one mediator of God and men, the man Christ Jesus:"
Meaning (commentary from the Douay Rheims): "One mediator: Christ is the one and only mediator of redemption, who gave himself, as the apostle writes in the following verse."
6. "Who gave himself a redemption for all, a testimony in due time
It doesn't say anything about not praying to God for others or to ask others to pray for us. I pray for anybody who needs prayers said. I ask Our Lady to pray for me. Her Son hears her pleas on our behalf, just as He hears our pleas for others.
Once you believe in the afterlife, which we all do, I don’t think sending a prayer request to a departed Saint, or anyone, is that hard to understand. Plus if one believes Saints were allowed to perform miracles on Earth. Perhaps this became excessive worship at times but no one ever mistook a Saint for God.