Why Not All Christians are in the First Resurrection

Understanding Why Not All Christians are in the First Resurrection (All Christians are Resurrected and Raptured, but not all Christians are in the First Resurrection. Nor all Christians in the First Rapture

Not everyone who is resurrected at 1 Thess. 4.15-17 at the last trumpet, which follows the rapture of the saints at the first trumpet, will be in the first resurrection because not all Christians fulfill the requirements of the 1st resurrection mentioned in Rev. 20.4. That is, not all believers are martyrs or overcomer believers while in the body of flesh and blood. Many believers though saved, still behave fleshly and thus, shall lose the reward of reigning, so they do not get to reign during the millennium, but will be made ready for the new city after. So God has accountability for believers by included some in the first resurrection and others not.