God is not the God of the dead. Therefore the saints are alive. If you asked your friends to pray for you it would be no different than asking that of say, Saint Augustine. And as for Mary we have Saint Cyril of Alexandria in the 2nd century to thank for ending the heresy that Jesus is not God. And since he is God then Mary is the Mother of God. Jesus is True God and true man. Saint Mary is alive just like the rest of the saints in heaven and we can ask her to pray for us. I don’t know what you believe but it’s probably more in agreement with the Catholic Church than you think.
Your problem is this: you don’t know what the Bible says.
Scripture tells us there is ONE mediator between God and men and His name is Jesus Christ. Prayers uttered dead men, even “saints,” are no more useful than praying to a stump. Christ and Christ alone is THE mediator. You don’t know that all of your “saints” are even in heaven.