Be true to thyself and it follows as night follows day that others cannot be false to thee." Of course this panacea offers only an inward healing, for none more readily admitted than he who wrote these sentences that in externals the true heart is often the first victim of the malice of the false heart.
Ever and again we find in the diary reflections on the general aspect of religion.

The Protestant churches seemed to him to fail to meet the aspirations of the natural man; that is the burden of his complaint against them all.

Some, like the Unitarians, did but offer man his best self and hence added nothing to humanity, while humanity at its best ceaselessly condemned itself as insufficient.

This insufficiency of man for himself, Calvinistic and Lutheran Protestantism in their turn condemned as a depravity worthy of the deepest hell, making man a wretch maimed in his very nature so cruelly and fatally as to be damned for what he could not help being guilty of.

Meantime the Catholic Church was seen by Isaac Hecker as having elements the most attractive.