A large segment of the WTS doctrines is contained in the proclamation that there will be an extenuating every lasting life
on earth for a select majority and a smaller select portion who are going to reside in heaven with God and Jesus Christ.
JWs are influenced to live their lives that is true and advantageous to live accordingly around that proclaiming assertion.
A purposed theory based from ancient mythological beliefs.
To be noted there are other theological beliefs in the after life from other religious beliefs separate from Christianity.
Here's a rather candid discussion on the concept of an after life that I thought was interesting.