So it is clear that in Rev that the 4 living creatures, 24 elders, and angels were in heaven and had the prayers of saints in a bowl. The word saints in the Bible implies believer (called out one), not one who has died and been declared a saint or such. There is no direct conclusion that these prayers were offered by people who had already died or not. That would be jumping to a conclusion. Paul addressed his Epistles to the saints in such and such place many times.
Romans 15:25
At present, however, I am going to Jerusalem bringing aid to the saints.
1 Corinthians 1:2
To the church of God that is in Corinth, to those sanctified in Christ Jesus, called to be saints together with all those who in every place call upon the name of our Lord Jesus Christ, both their Lord and ours
Matthew had to specify saints who had fallen asleep to so we would know they were believers who died. The word saints alone does cannot imply people who have passed.
Matthew 27:52
The tombs also were opened. And many bodies of the saints who had fallen asleep were raised,
Rev 5
7And he went and took the scroll from the right hand of him who was seated on the throne. 8And when he had taken the scroll, the four living creatures and the twenty-four elders fell down before the Lamb, each holding a harp, and golden bowls full of incense, which are the prayers of the saints.
Rev 8
3And 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, 4and the smoke of the incense, with the prayers of the saints, rose before God from the hand of the angel. 5Then the angel took the censer and filled it with fire from the altar and threw it on the earth, and there were peals of thunder, rumblings, flashes of lightning, and an earthquake.
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