The whole bible can be summed up in one verse. "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life" (John 3:16). This is what a christian believes in.
When a christian "dies" they do not die but through the power of Christ are given eternal life at the side of the Father. There are many different interpretations of the bible from Methodist to Baptist, however all God fearing men know the one undeniable truth, that Jesus died and through his perfect sacrifice they can believe on him and receive the gift of eternal bliss in heaven. Revelation 14:13.
After the death of a christian they will immediately open their eyes to the sight of either eternal bliss or eternal damnation. ""The time came when the beggar died and the angels carried him to Abraham's side. The rich man also died and was buried. and in Hades, being in torment, he lifted up his eyes and saw Abraham far off and Lazarus at his side" (luke 16:22-23). There is no suffering. God has prepared room for us in heaven "My Father's house has many rooms; if that were not so, would I have told you that I am going there to prepare a place for you?" (John 14:2). There we will spend our time until Jesus returns for his 1000 year reign, and then Satan is defeated in 7 years.
After the defeat of satan the earth will be erased and a new heaven and a new earth will be built to replace it. "Then I saw a new heaven and a new earth; for the first heaven and the first earth passed away, and there is no longer any sea" (Revelation 21:1). On this new earth we will spend eternity.