One of the best ways to understand Protestantism is to read the great writers of the past. Writers like Martin Luther, John Calvin, Thomas Watson. The Puritans and the other great writers of the past show how the modern church has changed and watered down the teachings of the Bible in the vain hope of trying to change the world instead of trusting in God. That does not mean there are no good books written now, there are just fewer good books now being written.
(Hebrews 4:12) For the Word of God is living and powerful and sharper than any two-edged sword, piercing even to the dividing apart of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart. (Hebrews 4:13) Neither is there any creature that is not manifest in His sight, but all things are naked and opened to the eyes of Him with whom we have to do.
"Examples do strangely charm us into imitation. When holiness is pressed upon us we are prone to think that it is a doctrine calculated for angels and spirits whose dwelling is not with flesh. But when we read the lives of them that excelled in holiness, though they were persons of like passions with ourselves, the conviction is wonderful and powerful." Cotton Mather