If you know your Old Testament, you know that the dead always went down to Sheol. You also know that the Greeks called this underworld Hades; thus, the Septuagint renders Sheol as Hades, and the New Testament follows suit.
When did people stop going down to Sheol and start going up to heaven?
The answer is when Jesus came again (i.e. in the coming of the kingdom of God) which occurred sometime in the late 1st Century A.D. He brought in a new heavens and a new earth in which there is no sea (for the sea gave up its dead). This had been prophesied by Isaiah long before, but it was prophesied again just before its occurrence by the book of Revelation. We therefore now live in that new heavens and new earth in which the righteousness of the kingdom dwells. People go up to heaven when they die for there is no longer a destination below.
If you do not believe that the last trumpet has sounded (1 Cor 15), and that the dead do indeed go to meet the Lord in the air (1 Thess 4), then you must believe that the dead still all descend to Sheol, and therefore that death still has its sting. I urge you to reconsider.
For a longer post on this subject, see Everyone Is Going to Heaven .
For those who would like a fuller explanation from the Bible that everyone is going to heaven, I am posting online a book: The Biblical Case for Everyone Going to Heaven.