Baltasar Gracián is a man of the 17th century, who wrote a good book called "The Oracle, a Manual of the Art of Discretion" or translated liberally and commonly, "The Art of Worldly Wisdom". He's like the Confucius of Christianity, . Highly recommended to be in any religious library.
Examples:
Aphorism #24
Keep the Imagination under control; sometimes correcting, sometimes assisting it. For it is all-important for our happiness, and even sets the reason right. It can tyrannise, and is not content with looking on, but influences and even often dominates life, causing it to be happy or burdensome according to the folly to which it leads. For it makes us either contented or discontented with ourselves. Before some it continually holds up the penalties of action, and becomes the mortifying lash of these fools. To others it promises happiness and adventure with blissful delusion. It can do all this unless the most prudent self-control keeps it in subjection.
Aphorism #109
Be not censorious. There are men of gloomy character who regard everything as faulty, not from any evil motive but because it is their nature to. They condemn all: these for what they have done, those for what they will do. This indicates a nature worse than cruel, vile Indeed. They accuse with such exaggeration that they make out of motes beams wherewith to force out the eyes. They are always taskmasters who could turn a paradise into a prison; if passion intervenes they drive matters to the extreme. A noble nature, on the contrary, always knows how to find an excuse for failings, if not in the intention, at least from oversight.
Aphorism #105 Don't be a Bore.
The man of one business or of one topic is apt to be heavy. Brevity flatters and does better business; it gains by courtesy what it loses by curtness. Good things, when short, are twice as good. The quintessence of the matter is more effective than a whole farrago of details. It is a well-known truth that talkative folk rarely have much sense whether in dealing with the matter itself or its formaltreatment. There are that serve more for stumbling-stones than centrepieces, useless lumber in every one's way. The wise avoid being bores, especially to the great, who are fully occupied: it is worse to disturb one of them than all the rest. Well said is soon said.