Fundamentalists often challenge the Catholic practice of asking saints and angels to pray on our behalf. But the Bible directs us to invoke those in heaven and ask them to pray with us.
Not only do those in heaven pray with us, they also pray for us. In the book of Revelation, John sees that "the twenty-four elders [the leaders of the people of God in heaven] fell down before the Lamb, each holding a harp, and with golden bowls full of incense, which are the prayers of the saints" (Rev. 5:8). Thus the saints in heaven offer to God the prayers of the saints on earth.
A glaring problem with this appeal is that Rev 5:8 doesn't say that Christians on earth were praying to Christians in heaven. The prayers of the saints in 5:8 (par. 6:9-11; 8:3-4) are prayers of martyred Christians in heaven. They aren't taking requests from Christians on earth. That's not in the text or context.