There is no salvation without it. It is saving knowledge. In knowing the true God we are saved. This knowledge purifies . Error or falsehood cannot deliver from sin, cannot purify the soul.
All error is impurity, unholiness.
All truth is good, and all truth respecting God sanctifies, expands, elevates. This knowledge makes us useful . It is like a light or fire within us that cannot be hidden. It is like a power within us which cannot but work. It is irrepressible.