Hence anyone who seeks for the true causes of miracles, and strives to understand natural phenomena as an intelligent being, and not to gaze at them like a fool, is set down and denounced as an impious heretic by those, whom the masses adore as the interpreters of nature and the gods. Such persons know that, with the removal of ignorance, the wonder which forms their only available means for proving and preserving their authority would vanish also.

This passage encapsulates the factors that influenced Spinoza's excommunication by Jewish religious authorities before the publication of his notable works on philosophy. Spinoza was a crucial philosopher during the Enlightenment, or the Age of Reason. Spinoza's theories were deemed in direct conflict with the Jewish faith. It was considered the highest blasphemy to question God's divine powers—in this case, miracles. To say that religious authorities exhibited "ignorance" by failing to embrace emerging scientific schools of thought, among other ideas put forth by Spinoza, led to his banishment from the Jewish faith.

By reality and perfection I mean the same thing.

Spinoza's Ethics deals with superstition versus realism. Spinoza discusses the general belief that something that is good should exist, while something that is bad should not. He instead argues that reality, particularly senses, should not be classified as good or bad. By removing the assumptions of good versus bad, he argues that all elements of reality are perfect. He asserts that it is theoretically false to let the world dictate the standards of good and evil. This is problematic to religious assertions of virtue versus vice, or holy actions versus sin.

Whatsoever is, is in God, and without God nothing can be, or be conceived.

This passage clarifies that Spinoza does in fact still believe in God. His religious ideas had simply been too radical and progressive compared to traditional religious beliefs. He argues that God has infinite powers, which is why it is too simple for things to be classified into good versus evil. Since God is divine, the reality that he has created is perfect. This is part of Spinoza's argument that God and laws of nature and physics should not be considered in conflict with one another. Rather, God creates and sustains the universe, and in order for the universe to function, it must obey scientific laws that God himself put forth.