15 While I was thus engaged there came to light certain fallacies of rash and wicked men, hopeless for themselves and merciless towards others, who made their own feeble nature the measure of the might of God's nature. They claimed, not that they had ascended to an infinite knowledge of infinite things, but that they had reduced all knowledge, undefined before, within the scope of ordinary reason, and fixed the limits of the faith. Whereas the true work of religion is a service of obedience; and these were men heedless of their own weakness, reckless of Divine realities, who undertook to improve upon the teaching of God.
Source: On the Trinity (New Advent)