look3467,
You have asked so many questions about salvation, which is a branch of Christian study, called Soteriology, so let me explain from the start.
God created Adam and told him not to eat of one tree in the middle of the garden of Eden, that if he did he would surely die,
Genesis 2:17. Since there was many trees and other things he could eat, this was a very small thing for God to tell Adam, but it was a way to show God that he truly wanted to obey Him. Eve, Adam's wife ate from the tree and gave some to Adam, and he are also, probably because he could not bear to live without Eve,
Genesis 3:6. Both Adam and Eve then became sinners, not only disobedient, but showed God that they did not want to obey Him, but wanted to listen to the Devil instead.
God then stated the first prophecy recorded in the Bible,
Genesis 3:15, which had to do with the coming of the Messiah, which was Jesus, and how Jesus would destroy Satan and Satan would bruise Jesus on the heel.
God did not want all of Adam's offspring to die forever, so God immediately formed a way for Adam's offspring to get back into God's love. God would send His son to earth, to give his life as a ransom sacrifice for all people who would accept Jesus sacrifice.
In Theology, this is called, Covenant Theology, or Federal Theology, which tells that by accepting Jesus' ransom sacrifice and following in his footsteps, any person could receive the same blessings that were to come to Adam.
God put Adam and Eve on earth to multiply and fill the earth with offspring, and have in subjection all animals,
Genesis 1:26-28. God made the earth for men to live on, forever,
Isaiah 45:18,
Psalms 37:29, 115:16. Contrary to the teaching of most religions, heaven was never promised to mankind, for there was no way for men to go to heaven. The only way they could die was to disobey God, and that would bring death, a returning to the ground as dust,
Genesis 3:17-19. After Jesus came to earth, which was six months after John the Baptist, and gave his life for man, the way was opened for some of mankind to go to heaven,
Matthew 11:12,13,
Hebrews 9:8. When the curtain or veil was ripped from top to bottom, at Jesus' death, the way was opened to heaven for a relatively small number of men to go to heaven to be Kings and Priests over the earth and it's inhabitants, both the ones resurrected and the ones who will through the Great Tribulation,
Luke 12:32,
Revelation 5:9,10, 14:1-5, 20:4-6.
Revelation 7:4 mentions a group of 144,000 who are sealed, these ones are the Little Flock mentioned at
Luke 12:32. The ones that will live on earth will be the ones that live through the Great Tribulation,
Revelation 7:14, and the ones resurrected back to earth from the graves,
John 5:28,29.
The thousand years mentioned at
Revelation 20:2-4, will be the Judgment Day, and all who live through that day will be subject to a final testing when Satan is released out of the Abyss, then they will be granted Eternal life, having the same blessings that Adam and Eve would have received if they had not sinned against God. God wants all to live, but all who want to live MUST accept that Jesus died for them and then follow Jesus' footsteps as closely as possible, 1Peter 2:21. We are very close to the time that Jesus will return to earth. When he returns, he will judge all who are alive at that time, to be worthy to live into the Judgement Day or be destroyed,
Matthew 25:31-46.