How did believers die with Christ?
Believers died with Christ by being buried with Him through baptism into death, not water baptism. As Christ truly died, old Adam had to die, and in the mind of God they were engulfed in His three-day tomb experience, so as He died, they died.
Les explains in Romans, verse 4, that believers are buried with Christ by baptism into death. This is not the water baptism that denominations use to baptize a person into a church or denomination; it is the work of the Almighty Himself. It means that just as Christ was really dead—three days and three nights in the tomb, not merely unconscious—so the same had to happen in the realm of old Adam. Old Adam had to die, and we have to be sure he is dead. As Christ died, believers died; as He was buried, they were buried in the mind of Christ, the mind of God. God saw them in the tomb and engulfed in Christ’s three-day tomb experience. They do not remain there but are resurrected out of it, just as Christ was. Les notes that Paul never drops this theme and turns to Ephesians as an example.