See the context, John v, 25-29, which quite bears out St Thomas.
The great proof of our corporeal resurrection is the corporeal resurrection of Christ: the first fruits, Christ, then they that are Christ's at his coming, 1 Cor. xv, 23. If the Christ seen by His disciples after His death was a mere wraith, or ghost, then there is no resurrection of the body awaiting us. I take it some ghost stories are true statements of an objective reality seen. But the appearance of the ghost is not the removal of the body from the grave. The corpse lies still where it was laid, even while the ghost walks. Now, Holy Scripture assures us, this is precisely what did not happen in the case of Christ. The body was not in the tomb (Matt. xxviii, 6: Mark xvi, 6: Luke xxiv, 3: John xx, 2). St Peter appeals publicly to the fact in Jerusalem a few weeks after, and says that Christ's flesh did not see corruption (Acts ii, 24-32). The Jews, Annas the high priest and Caiphas and John and Alexander, and all that were of the high priest's kin (Acts iv, 6), had every interest in producing the body of the Man, whose resurrection was proclaimed (Acts iv, 10), and whose blood was being brought upon their heads (Acts v, 28). They did not produce it, they were unable to trace it. All that they could produce was the lame story of the 'sleeping witnesses' (Matt. xxviii, 11-15). The 'wraith theory' is a direct contradiction of the witness of the Apostles (Acts iv, 33). It transforms the upper chamber (Acts i, 13), where the spirit of truth descended (John xvi, 13: Acts ii, 4) into a den of thieves (Mark xi, 17) A Christian at least will beware of such a theory.
Of God and His Creatures: 4.79