Resurrection has been promised all along. There is a resurrection to an Edenic garden state or a resurrection to the fires. In Q4:87 after the long discussion about fighting in the way of God and martyrdom he concludes with the assertion, "God -- (there is) no God but Him. He will indeed gather you to the Day of Resurrection -- (there is) no doubt about it. Who is more truthful than God in report?"
Q4: 88-92 is another look at hypocrites. This who have disbelieved are an active force in trying to convince believers to turn away also. His prescription? "If they turn back, seize them and kill them wherever you find them." He then creates exceptions for those who have become part of a people with whom Muhammad has a treaty, or those who renounce fighting him or their own people. In such cases God has not "made a way" for Muslims against them. But, "If they do not withdraw from you alone, and offer peace (the greeting al-salam), and restrain their hands, seize them and kill them wherever you come upon them. Those (people)--We give you clear authority against them."
Q4:92ff forbids believers killing other believers. And given the preceding section, it becomes hard to find a justification for the killing of any Muslim by another Muslim, in my opinion this far into the Qur'an. In Q4:94 he goes further, warning those going on campaign not to define others as unbelievers in order to win the spoils of battling with them. There are other more important spoils to be had than earthly wealth.
For those who sit at home instead of campaigning...they lose rank in the community. God's favor is greatest on those who "struggle."
Tomorrow: Those to weak to emigrate and Traitors