Who is Paul primarily talking about in 1 Corinthians 15:22 when he says 'in Christ shall all be made alive'?

Les explains that in 1 Corinthians 15:22 Paul is directing his attention primarily to the believer, while also remembering that it will be the power of God that resurrects the lost as well at a future time. Les says Paul is dealing with the believing element, so “every man in his own order” means every believer in his own order. That word “order” is a military term, like a company or battalion, an organizational group. So every human being in the human race will be resurrected, but in his own particular company. Christ is the firstfruits, the first group of resurrected people, and afterward—not simultaneously—they that are Christ’s at His coming. That group is the church-age, grace-age believer, the body of Christ. Then comes the end, which is after the tribulation.