It is easy to say we should believe in anything just because the Bible says so. Ultimately that is the reason. This is especially true of heaven and hell because they cannot be proven with the earthly human experience. Science cannot verify their existence. Nobody can testify to them except Jesus (Jn 3:11-13). Some have had visions (Gen 28:10-15, 1Ki 22:19-22, Is 6:1-13, 2Cor 12:2), but only Jesus has actually been there and on earth. He came from heaven as God, so He can tell us (Jn 1:1-3 & 14, Jn 3:31, Jn 6:33-51, Jn 8:23). Since we have already discussed why we should believe in Jesus, we can trust His testimony to be true. He said there is a place called heaven. He mentioned it 34 times in Matthew, and used the phrase “kingdom of heaven” 31 times in that book. He spoke of heaven 14 times in John. We also dealt with why we should believe the apostles. They wrote Matthew and John, so those are also their testimony. From the book of Acts to 1John, they mention heaven 56 times; and John mentioned it another 56 times in the book of Revelation alone. It comes from the Greek word ouranos. It could mean the visible sky, the universe, or the dwelling place of God and angels. It is also mentioned another 344 times in the Old Testament as shamayim, which could also mean the earth’s atmosphere, the sky which holds the stars (the universe), or the dwelling place of God. This is why Paul talked about the third heaven (2Cor 12:2).
The Bible also speaks of hell. This word appears 54 times. The Old Testament speaks of sheol. This word is translated 31 times as hell, 31 times as the grave, and 3 times as the pit. In the New Testament the word hell appears 17 times. Jesus spoke of it 9 times, the apostles 4 times, and the book of Revelation specifically mentions it 4 times. It is called gehenna 9 times. Gehenna comes from the Hebrew word Hinnom which refers to the valley of the son of Hinnom. This was an area south and east of Jerusalem where an idol called Molech was worshipped. Molech was a statue which had a live fire burning inside. Children were placed in the arms of the idol and burned alive. After this idol was destroyed, the people used the valley for a garbage dump. Its history, its stench, and its use thus made it a fit symbol of hell. It is also called Hades after the pagan god also known as Pluto. This word is used 11 times for hell, and once for the grave. At the end, those in hell will stand for final judgment and be sent to the lake of fire (Rev 20:11-15).
There are several reasons besides the basic “the Bible says so” to believe in heaven. If there is no heaven, there is nothing to hope for outside this world and beyond this life. Paul said this is enough to make us miserable (1Cor 15:19). The same things that the hope of the resurrection gives a Christian are the same things the hope of heaven gives (see chapter 6). That is the destination of the resurrected (Jn 14:1-3, 1Thes 4:13-18. Phil 3:20-21). If there is no heaven, then the only reward for the righteous is in this life. We should be thankful for every blessing God gives us in this life. We should not serve God solely for a reward, but for love of Him (Gen 15:1). However, God fully expects and encourages us to seek a reward (Mt 5:12, Mt 6:1-6 & 16-18, Mt 10:41-42, 1Cor 3:8 & 14, 1Cor 9:17-18, Col 2:18, Col 3:24, Heb 10:35, Heb 11:26, 2Jn 8). If God is keeping track of every time someone gives a cup of water to a disciple in order to ensure their reward, then He is interested in us receiving it. The Bible speaks of crowns given to the righteous (1Cor 9:25, 2Tim 4:7-8, Jam 1:12, 1Pet 5:4, Rev 2:10, Rev 3:11, Rev 4:4 & 10). Although heaven itself is a reward (Mt 20:1-16), there will also be individual rewards for those who go there (Mt 13:23, Mt 25:14-23, Lk 19:12-27, Rom 14:10, 1Cor 3:12-15, 2Cor 5:10).
If there is no heaven, there is no hope when a loved one dies. The Christian is instructed to not even sorrow when another Christian dies like someone who has no hope, and to be comforted in their death (1Thes 4:13-18). We sorrow not for them, but for ourselves because we will miss them. We should have a celebration because someone made it into the kingdom of heaven (Lk 10:20, Lk 15:7). They are much better off than those they left behind. They get to be with Him in paradise (Lk 23:43, Phil 1:23).
Is heaven a geographical location, or a spiritual condition of enhanced relationship with God? Is Revelation 21 literal or symbolic? Verses 2 and 9 say the city is Lamb's wife, which is the church.
Heaven is not about a change in location or circumstance. It is about a change in condition. It is about putting off the sinful flesh, and inheriting the nature of God (Rom 8:19, 2Cor 5:5, Eph 1:14, Heb 9:15, 1Pet 1:4. It is about being able to handle and abide in the concentrated presence of God (Ex 33:18-23). It is about fulfilling the kingdom. This is the emphasis of the scriptures, not a shiny place without bills etc.
If there is no hell, there is no final justice for the wicked. People often begrudge that fact the people seem to get away with things. People say life is not fair. Christians know better. Heaven and hell make life fair. Ask the rich man and Lazarus (Lk 16:19-31). God not only reckons with people in this life, there is also a hell waiting for the unrepentant. It is not that Christians should rejoice over people going to hell. God does not even do that (Eze 18:32, Eze 33:11). It is that we can know there is a just God who brings every man into account (Mt 12:36, Acts 17:30-31, Rom 14:12, 1Pet 4:5), and rewards every man according to his work (2Sam 3:39, Ps 91:8, Jer 25:14, Mt 16:27, 1Cor 3:8, 2Cor 11:15, 2Tim 4:14, Rev 20:12-13, Rev 22:12). Just as there are individual rewards in heaven, so there will be individual punishments in hell (Deut 32:32, Ps 86:13, Mt 10:15, Mt 11:22-24, Lk 12:45-48). This should generate fear that motivates us to do right (Job 28:28, Prov 14:27, Prov 16:6, Mt 10:28, Acts 9:31). Just as there is nothing wrong with seeking rewards, we ought to fear hell. These are God’s values. That fear should also move us to seek the souls of those who are in danger of it (Jude 23).