By the book
"Be perfect, therefore, as your heavenly Father is perfect." Matthew 5.48
In the 1986 comedy 'Clockwise', John Cleese plays a punctilious headmaster who gets his come-uppance at the very moment of his glory, when his perfectly ordered world unravels. German philosopher Immanuel Kant was also a stickler for things being done correctly, though perhaps not as accident-prone as Cleese' character! Kant's commitment to getting everything right led him to some significant conclusions and insights. It even spawned a new endeavour in philosophy called "deontology" (from the Grrek word meaning "duty").
Kant's uncompromising approach took him all over his subject and enabled him to square the odd circle too, such as resolving the ancient contradiction between empiricism (everything must be verified through experience) and rationalism (which establishes truth as a first principle). He did this by demonstrating how the very tools we use to verify knowledge are the product of our capacity to work things out theoretically.
Kant was a "transcendental idealist" because he discerned that ultimate reality lies beyond the realm of human experience. He was also a Christian, so some have accused him of pinching his ideas from his theological heritage. Were that to be true it would undermine Kant's commitment to his principles. It is more likely that his faith as a Christian informed and guided his work as a philosopher., with the happy consequence of further illuminating the search for truth which philosophy conducts on behalf of all humanity. For is it not the case that Jesus exposes the hypocrisy of those who claim to be righteous and are not, while providing the means of righteousness to those honest enough to admit that they lack it?