Kant certainly was sympathetic with the metaphysical tradition of rational theology that he criticized.

Virtues consist not only of acting in certain ways, but in ways of caring and feeling.

What is central to morality is rational self-constraint (acting from duty), in cease where there is no other incentive to do your duty except that the moral law commands it.

Philosophy is about getting the facts right, but it is also about thinking rightly about them. Philosophy is more about the latter than the former.

Freedom is a permanent problem for us, both unavoidable and insoluble.

Fichte thinks that the mutual recognition of one another as free beings belongs among the transcendental conditions of self-consciousness itself.

It was an important part of Mendelssohn's philosophical and religious view that the traditional rationalist proofs for God's existence should be sound an convincing. Kant thought they were not. So Kant's critique was world-shaking for Mendelssohn.