indefectible

The mechanism of the United States, like that of the universe, reposes on indefectible laws and uncontrollable forces.

Under these varying 226 modes and presentations it permanently abides as the indefectible substance of the spirit.

The church is therefore, by her own divine constitution, by the very principle and law of her existence, indefectible.

Indefectible, in-de-fekt′i-bl, adj. incapable of defect: unfailing.

And since at no time must it cease to teach, it must be indefectible.