Most other Christians believe that when a person dies their soul leaves their body and then rises up to heaven immediately after death.
But Jehovah Witnesses believe that the body when dead stays in the grave until Jesus resurrects the person after God's Kingdom, or government, is ruling over earth.
Another thing is that Jehovah Witnesses believe that Jesus died on a pole through torture and not on a cross like other Christians believe.
As for myself I don't believe in a god, Jesus or any heaven at all.
I hate when Jehovah Witnesses show up at my door trying to get me to believe in their beliefs as well and I have tried kindly asking them to leave but now I have to slam the door in their face or not open the door.