Eschatology, the study of last things or the end of the world, has been an unnecessary stumbling block and source of division within the church. Believers should approach the topic with grace and charity, especially since many details about the end are derived from apocalyptic literature which tends to be metaphorical and vague.
Fortunately, there are areas within eschatology in which all should agree (dogmas), areas of flexibility (doctrines), and areas of freedom (details).
Areas where all believers should agree include the words spoken by Jesus Himself. During His ministry on Earth, Jesus Christ was very clear on several key points regarding the end, first of all taking it for granted that there will in fact be an end (Mark 13). Most important is that in the end God wins (Matthew 25:41). As a significant component of the end, Christ assured His disciples that He would return (John 14:3) and that His second coming would be in bodily from, the same way as He ascended (Acts 1:11).
Jesus also stressed that no one knows when the end will come (to the disappointment of modern end times prophets) (Matthew 25:13). Jesus even went so far as to state that not even the angels nor He in His humanity knew the date of the end (Mark 13:32-33). However, Jesus did indicate that there will be signs to defend believers against false claims. Room for interpreting exactly what these signs have or will look like is crucial since they could be read literally or metaphorically. Furthermore, the extent of the signs is ambiguous allowing that some of the signs may have already been completed. Regardless, we are to eagerly look forward to Christ's return and the signs which will include: a period of tribulation (Mark 13:8), the appearance of false prophets & miracle workers (v22), cosmic or atmospheric disturbances (v24-25), the rise of the lawless one or antichrist (Revelation 13), and the salvation of Israel (Romans 11). However, the most important sign Jesus gave involves the active participation of believers following His final command, the Great Commission. For Christ revealed that "...this gospel of the kingdom will be preached in the whole world as a testimony to all nations, and then the end will come" (Matthew 24:14 emphasis added). Thus, a good eschatology is a good Missiology, but believers should remain ready at all times for no one knows the final hour and Christ could return at any moment.
Areas where believers should be cautious include the eternal state. One crucial element of the gospel is the existence of Heaven for those who accept Christ's substitution, and Hell for those who refuse (Matthew 25:31-46). Denying Heaven leads one to fall into Naturalism, while denying Hell leads one to fall into Universalism, and both empty the Cross of its power. Other positions such as Annihilationism and Postmortem conversion are held by Christians, but raise questions about the holders Bibliology since neither view is supported by scripture.
Beyond their physical existence, complete unity regarding the details of Heaven and Hell is unnecessary. Since many of the descriptions could be taken as metaphorical or as the author's best description of the indescribable. In the end, whether Heaven's streets are made with gold that is also glass-like and transparent is really irrelevant (Revelation 21:21). Likewise, it is a mystery whether Hell has literal flames (Mark 9:43) when it will also be dark (Matthew 25:30). For the sake of unity, it is best to conclude that Heaven and Hell are places of eternity in God's presence and separation from God's presence respectively. Details regarding the intermediate state (sheol vs. paradise, soul sleep, etc.), should similarly not become sources of division.
Areas where believers should extend grace and charity include the millennium. Only one passage in scripture uses the term millennium (Revelation 20:4-5) and nuanced interpretations should not be enforced dogmatically. While each specific millennial view subtly influences how believers live their lives, often times life circumstances can impact the believers understanding of the three major views. Postmillennialism holds that the world will slowly be Christianized so that slowly a millennial age will emerge, and tends to become more popular in times of world peace and prosperity. Amillennialism holds that there is no millennium or that we're living in it now as an extended period of the Church, and tends to be attractive due to its simpler understanding of last things. Premillennialism holds that following the tribulation, but before the eternal state there will be literal 1,000 year reign of Christ with His saints on Earth, and tends to be more attractive during periods of persecution.
While many passages seem to support a Premillennial view (Isaiah 11:2-9), grace and charity should be extended between those differ whether believers will be caught up with Christ (the rapture 1 Thessalonians 4:17) before, during or after the tribulation. Again the details of Dispensationalism and Historic Premillennialism should not become a source of division.
Ultimately, believers should take heart that God is in sovereign control of this world, including its end and eternity beyond. Believers should eagerly anticipate the day when they can see Jesus face to face (1 John 3:2) and through His death on the cross enter into God's presence for all eternity. Since God may call us home at any moment, whether individually or worldwide, we should live each moment in light of the next world sharing the gospel freely with everyone in hopes that they won't spend eternity separated from The Lord God Almighty.