Seems to me you have brought up two distinctive subjects or points here.
#1. Yes, the loss of a loved one can often be unspeakable grief. How we all wish this could be avoided.
There is a reason why we wish this could be avoided....it was never meant to happen. Humans are not 'programmed' for death like animals are. If Adam and his wife had simply obeyed that one command in the garden...they would still be alive today, (Gen 3:3) they would be young and healthy and enjoying life in paradise conditions with all their offspring. There would have been no sickness, no aging and no death if sin had not entered the world through that one act of disobedience. (Rom 5:12)
#2. Yes, we can know that there is life after death. God is not nearly as unknown as some of your peers may want you to believe.
Statements without something to back them up are a bit useless on a debate forum thau. There is no afterlife spoken about in the Bible except by resurrection in the flesh, for the majority of mankind. (John 5:28, 29)
The signs are everywhere for all generations.
What 'signs' would that be?
No one has to be an educated pupil to understand this. God also promises heaven to almost anyone who would sincerely want it.
That is not really true. God did not choose to take everyone to heaven...in fact only a limited number will ever go there. These will make up a ruling body with Christ in his kingdom. They are specifically chosen by God for this role. It is a 'heavenly calling'. (Heb 3:1)
If Adam had not disobeyed his Father, no one would ever have gone to heaven. Jesus' sacrifice would not have been necessary and no kingdom would have needed to reconcile mankind back into an acceptable relationship with God. (2 Cor 5:19, 20)
I might point out "actions speak louder than words."
Absolutely. :yes: (James 2:18, 19)
So point #2 does not take away the sorrow in point #1 but helps, as it most assuredly gives promise and hope.
I agree that we need hope and comfort because of #1. But understanding why death takes place explains why we that need hope and comfort. The fact is, the Bible does not teach your #2. Understanding God's original purpose for the earth and man upon it explains everything. There is no immortal soul because man did not need one.
Living forever in paradise on earth was possible because God had another 'tree' in the garden that guaranteed that life would never end. Once man became sinful, access to that tree was permanently denied. (Gen 3:22-24)
When Jesus' friend Lazarus died and was laid in his tomb, Jesus said he was "sleeping" (John 11:11-14) He said he was going to 'wake him from sleep'.
Where was Lazarus before Jesus woke him up? If he had gone to heaven, then Jesus was doing him no favors by bringing him back to the problems of this life, only to get sick or old and die again.
The 'soul' that was Lazarus was brought back to life in the flesh. Every single resurrection performed in the Bible was back to life on earth, reunited with loved ones.
This is the hope and promise.