To describe hell Jesus used language like “eternal fire” (Mat 25:41), “fire of hell” (Mat 5:22) and “blazing furnace, where there will be weeping and gnashing of teeth.” (Mat 13:42) and “darkness, where there will be weeping and gnashing of teeth.” He did this to describe the eternal fate of those who do not repent of their sin in order to be included in the kingdom of heaven.
The kingdom of Heaven is spoken of quite a bit in the Bible. It is the same as the kingdom of God. Think of the kingdom parables in Matthew 13 which describe heaven. Other scriptures describe heaven as a “house [with] many rooms” that Christ is preparing for us (John 14:2 ; 2 Cor 5:1; taken up to during his ascension (Luke 24:50-51)), which is unimaginable (1 Cor 2:9), eternal (2 Cor 5:1) a “better country” or “city” (Hebrews 11:16, 13:14; Rev 21:1-5, 21-25) which includes “eternal life” (John 3:16), and where “he will wipe away every tear from their eyes, and death shall be no more, neither shall there be mourning, nor crying, nor pain anymore, for the former things have passed away” (Rev 21:1-5). The new Heaven will replace or renew the old heavens and earth (2 Cor 5:1; Rev 21:1-27), and God will dwell visibly so we can have intimate relationship with him (Rev 21:1-4; 22:1-5) and where worship continue (Neh 6:9; Rev 22:1-5). It is a secure place to “store up treasures”—what we hope for (Mat 6:19-20; 19:21; Luk 12:33-34), a kingdom of safety from evil attacks (2 Tim 4:18), where nothing is accursed (Rev 22:1-5) and righteousness dwells (2 Peter 3:13). Heaven belongs to those who trust in Christ like children trust (Mat 24:35), where “our citizenship is”— a source of authority (Phil 3:20).
The idea that Heaven is a different dimension that exists concurrently with our space-time dimension is a comic-book version of Christianity. The truth is that heaven and hell speak more about the state of men and women after the resurrection, after the final judgement at the end of the age, than a spiritual space. These are future realities. Or more accurately, hell is a future reality, and the kingdom of heaven has arrived (in the person of Jesus), is presently being established through the ministry of the Spirit-filled church, and will continue to become more established, here on earth, until Christ returns some time in the future—then it will be fully complete. Think of Heaven as an invading army, slowing taking over the realm, from the hearts of men to the various spheres of influence in this world, rather than a place you go to when you die. It’s more like a time you arrive at when you’re resurrected than a location – but if you press for a location, you’d have to say it will be right here on earth rather than in the sky.