1 Corinthians 6:2-3
2 Or do you not know that the saints will judge the world? And if the world is to be judged by you, are you incompetent to try trivial cases? 3 Do you not know that we are to judge angels? How much more, then, matters pertaining to this life!
Revelation 8:3-4
3 And another angel came and stood at the altar with a golden censer, and he was given much incense to offer with the prayers of all the saints on the golden altar before the throne, 4 and the smoke of the incense, with the prayers of the saints, rose before God from the hand of the angel.
These two verses talk about the relationship between people and saints. If saints (Rev 8) are already in heaven, what do they need to pray for? They're passing along prayers of the people whom they will judge.