The phrase "censorious thoughts" comes from Jonathan Edwards's chapter on this topic in Charity and Its Fruits. Here's a quote:
And so persons are censorious when they condemn others as being unconverted and carnal men because they differ from them in opinion on some points that are not fundamental, or when they judge ill of their state from what they observe in them, for want of making due allowances for their natural temperament, or for their manner or want of education, or other peculiar disadvantages under which they labor, . . . setting up themselves, and their own experience, as a standard and rule to all others; not being sensible of that vast variety and liberty which the Spirit of God permits and uses in his saving work on the hearts of men. . . . In all these ways, men often act, not only censoriously, but as unreasonably (in not allowing any to be Christians who have not their own experiences) as if they would not allow any to be men who had not just their own stature, and the same strength, or temperament of body, and the very same features of countenance with themselves.
