International Standard Bible Encyclopedia (1915)

Peculiar to Paul’s majestic argument on the resurrection: celestial verses terrestrial bodies (1Co 15:40) with reference possibly to sun and moon, etc., but more probably to the bodies of angels in distinction from those of beasts and mortal men (compare Christ’s words, Mt 22:30; Lu 20:36); including also doubtless in the apostle’s thought the resurrection-body of Jesus and of the saints already taken-into glory. Light is thrown on its meaning by the rendering of the same Greek original as "heavenly places" (Eph 1:3,20; 2:6; 3:10); "heavenly" (1Co 15:48). Hence, "celestial" as used by Paul indicates the soul’s continued life beyond the grave, the spiritual body of the redeemed in heaven, who, in Christ, have put on immortality.

Dwight M. Pratt