How do I know my spiritual progress?

The higher one rises here the more transparent [becomes] one's self-protecting veil of ignorance about oneself. 

Truth is the most withering thing in the Universe and it requires the greatest courage to face the truth about oneself. No matter how humble we fancy ourselves, the discovery awaits us that we are more arrogant than anyone we ever met. 

When revelation comes it sets out every detail of our lives with a clean-cut distinctness no eyes can mistake, no charity cover. 

Each soul must face himself alone at some time—look, see and judge. Then, however prostrated, rise and begin to fight his way up toward perfection, undaunted and fearless, with hope as well as courage.

You will meet your trial, face it, and after the shock rise up with the courage that was always yours.