From the section titled “The Conversion of Souls and the Prosperity of the Church depend on the Degree of the Pastor’s Piety”:
As is the love of Christ in his own soul, so will the minister’s zeal for the perishing souls of those committed to his care; so will he long for the glory of Christ; and so will he pray and work and strive in his heavenly calling; and so ordinarily will be his success in that calling. There is nothing else in this wide world that can properly constrain him to put forth the efforts that are needed. It was this which the apostle Paul said constrained him, and so it must be with every one who would follow in the successful course of the apostle. All other motives will soon lose their impelling energy, but this will grow strong and stronger. It will find means for removing or overcoming obstacles, and still hold its onward course. Hence, in the quiet seclusion of his closet, when the pastor’s heart is warming through communion with God, there is the best possible preparation going on for the conversion of souls.
Then the piety of the church will generally rise about as high as that of its minister. A cold, worldly-minded pastor is sure to have a cold church. A living pastor will have a church in which life and joy and prayer will abound. How can it be otherwise, since his ministrations permeate the whole life of the body? He is the appointed agent for edifying the people of God in their most holy faith, and their spirituality cannot be expected to rise higher than his. There doubtless are exceptions, but the general rule is, that the measure of devotedness in any particular church may be gauged by that of the pastor’s heart. Should he rest satisfied while there is any coldness there?
– T. Murphy, Pastoral Theology, pp. 47-48 (emphasis mine).