You have already acknowledged that Saint Paul asked the saints to pray for him, so absent a verse that suggests that sainthood doesn't survive in Heaven, your statement is without merit.
Do you belong to one of these sects that denies the Apostle's Creed?
Because another Christian took the time to pray for me is the entire reason that I got saved and my life was transformed as a result.
How do you know that others weren't praying for you?
I pray that God bless you and lead you to the Truth and deliver you from false doctrine.
Believing that our Lord gives us eternal life IS NOT a false docrine.
The Bible teaches the exact diametric opposite approach to understanding scripture.
Acts 17:11
Now the Bereans were of more noble character than the Thessalonians, for they received the message with great eagerness and examined the Scriptures every day to see if what Paul said was true.
Your approach is like a heroin junkie saying "Well, the Bible doesn't say not to shoot heroin into my veins so it must be okay".
While the junkie may be technically correct in that the bible doesn't specifically mention syringes, heroin addiction is just another form of drunkeness and the bible is very clear that drunkeness is a sin.
The bible is also very clear that communicating with the dead is a sin.