Let him who is to be appointed be chosen because of the merit of his life and because of his learning, even though in the community he may be lowest in rank. . . . Let him who has been appointed Abbot always bear in mind what a burden he has taken on himself, and to whom he will have to give an account of his stewardship; and let him know that it behooves him rather to serve his brethren than to lord it over them. He must, therefore, be well versed in the Divine Law, that he may know whence to bring forth new things and old; he must be chaste, sober, merciful; and always exalt mercy above judgment that he himself may find mercy. Let him love the brethren whilst he hates their vices. And in the very correction of the brethren let him act prudently and not go to excess, lest, seeking too vigorously to cleanse off the rust, he may break the vessel. Let him ever keep his own frailty before his eyes and remember that the bruised reed must not be broken. By this we do not mean that he should suffer vices to grow up, but that he could cut them off prudently and with charity, according as he shall see that it is best for each, as we have said; and let him seek rather to be loved than to be feared.
Seems to me the direction the 7th Century St. Benedict offered in his Rule about what is needed in an Abbot (the leader of a monastery) is timeless wisdom that could apply to pastors today (or any Christ-follower in a leadership position):