First of all, praying to the dead is a sin. The dead are no less dead now than they were in OT times when that was made clear by the Word of God. But why not simply pray the way the bible says to pray and add nothing to that. Isn’t the bible sufficient?
That is not Scriptural. The saints in heaven are NOT dead. They are in the complete fulness of life in God, to which we aspire on earth.
But in the account of the bush, even Moses showed that the dead rise, for he calls the Lord 'the God of Abraham, and the God of Isaac, and the God of Jacob.' He is not the God of the dead, but of the living, for to him all are alive."
Luke 20:37-38
Then at the Transfiguration, Christ appears with Moses and Elijah - living, not dead.