Ecclesiastes 9:10 Whatever your hand finds to do, do it with all your might, for in the realm of the dead, where you are going, there is neither working nor planning nor knowledge nor wisdom.
So you take the Old Testament as the last word on every doctrinal question? Nothing new was revealed in the New Testament?
If you take Ecclesiastes as the last word on eternal life, then you must deny the Resurrection.
No, but believers have not yet been raised. Show one instance of the apostles praying to those departed from this earth. Paul said to "boldly go before the throne" of the Father not some dead saint.
Hebrews 4:16 Let us therefore come boldly unto the throne of grace, that we may obtain mercy, and find grace to help in time of need.