Does a person enter heaven (or hell) immediately after death, or can we "hang around" somewhere else? What about people who say they have visited Heaven and come back? And is there any benefit in praying for someone who has already died in unbelief?
The Bible teaches that after death comes to the body, our spirit exists eternally. After the believer's body dies, angels will escort our spirit to Jesus' presence in the Throne Room. The unbeliever's spirit descends to Hades (Hell) to wait in torment until they are resurrected into new bodies for a day of judgment at the Great White Throne Judgment described in Revelation 20. Believers receive new bodies on a different day of Resurrection, also called the Rapture.
These courses are set permanently at death. There is no second chance for salvation, and no one can alter their destiny following death, as Hebrews teaches:
Heb. 9:27 And inasmuch as it is appointed for men to die once and after this comes judgment,
Heb. 9:28 so Christ also, having been offered once to bear the sins of many, will appear a second time for salvation without reference to sin, to those who eagerly await Him.
Therefore, praying on behalf of the souls of departed unbelievers may be understandable, but it is a desire contrary to scripture and therefore we can't expect the Lord to honor a prayer that asks Him to act contrary to His own word.
Regarding, the stories of people who have visited heaven, we believe these stories are something other than a true vision of Heaven. These visions are likely the result of demonic deception, hallucinations or even outright lies. Most of the stories are sensationalized by the media, but as Christians, we don't gain our knowledge of the spiritual realm from such experiences. In fact, it is dangerous to incorporate worldly experience into our theology, since our world and even our sense lie to us. The Bible was given to us so that we might have all we need to understand God and His plan fully. As Peter explains:
2Pet. 1:2 Grace and peace be multiplied to you in the knowledge of God and of Jesus our Lord;
2Pet. 1:3 seeing that His divine power has granted to us everything pertaining to life and godliness, through the true knowledge of Him who called us by His own glory and excellence.
Consequently, we encourage you to seek the truth of God through His word and not to rely on these supposed experiences to form your understanding of spiritual things. Our experiences and emotions easily manipulated by the enemy to fool us. As Paul said:
2Cor. 11:14 No wonder, for even Satan disguises himself as an angel of light.
For more information on this area of study, we recommend you follow our Revelation Bible study.