You mean that which is demonstrated, without/before the demonstration.
The demonstration (image, life) in the mind, before it is spoken in the action.
But such a “that” or “life” unspoken — is more decaying than open rebuke.
Fruit rotting on the vine, diseased.
Faith without action is dead weight.
That’s interesting that Thomas influenced the Upanishads & combatting gnosticism in India. I haven’t studied much about that.