After Jesus ressurection certain ones would be chosen / sealed by God to go to heaven (144000 faithful servants-Rev 7:4). The majority of these ones are a sleep in death at the present time until the marriage of the lamb-soon to take place.
1 Thes 4:13-18- Moreover, brothers, we do not want YOU to be ignorant concerning those who are sleeping [in death]; that YOU may not sorrow just as the rest also do who have no hope. 14 For if our faith is that Jesus died and rose again, so, too, those who have fallen asleep [in death] through Jesus God will bring with him. 15 For this is what we tell YOU by Jehovah’s word, that we the living who survive to the presence of the Lord shall in no way precede those who have fallen asleep [in death]; 16 because the Lord himself will descend from heaven with a commanding call, with an archangel’s voice and with God’s trumpet, and those who are dead in union with Christ will rise first. 17 Afterward we the living who are surviving will, together with them, be caught away in clouds to meet the Lord in the air; and thus we shall always be with [the] Lord. 18 Consequently keep comforting one another with these words.
The choosing of these ones has been ongoing down through the centuries from the millions of other Christians during that time right up to the present.
These tried and tested ones will serve as kings and priests alongside Christ over/on/upon the earth. Rev 5:10 -"You have made them to be a kingdom and priests to our God; and they will reign upon the earth."
They are the ones who go to heaven to be with Christ for such a purpose.
Please Note Jesus own words at Mat 5:5. Even Jesus pointed out that certain ones would inherit the earth.
That is why Jesus correctly said the following in his sermon on the mount, when speaking about those who will be going to heaven and those who would reside on earth. Though not fully grasped at the time, It is only through spiritual insight that people could fully understand the meaning of his speech. Instead of it being contadictory, it makes absolute sense in light of the inspired writings that had come about since then.
1Now when he saw the crowds, he went up on a mountainside and sat down. His disciples came to him, 2 and he began to teach them saying:
11 "Blessed are you when people insult you, persecute you and falsely say all kinds of evil against you because of me. 12 Rejoice and be glad, because great is your reward in heaven, for in the same way they persecuted the prophets who were before you.