What kind of body is buried in the grave?
The grave receives the old physical body, which is already corrupt, prone to disease and failure. It is a body of corruption, not a spiritual body like Christ's resurrected body. Flesh and blood cannot inherit the Kingdom of God, so this corrupt body is buried, awaiting resurrection into a new body fashioned after Christ's.
Les explains that flesh and blood cannot inherit the Kingdom of God, and corruption does not inherit incorruption. The spiritual body, such as Christ's resurrected body, is not put back in the tomb. What goes into the grave is this old physical body, already corrupt and prone to disease and failures of various kinds. It is that body of corruption that is buried and placed in the ground. But when it comes out in resurrection power, it will be a new body, fashioned after Christ's body. Les also points to Ephesians 1:18 as Paul's prayer on behalf of believers, expressing a mind-boggling request he knows will be experienced either in this life or the next.