When we are in ministry, we offer ourselves to others, for God’s sake, for the sake of those we serve, and yes, for our own sake. Ministry is not just about giving to others, nor is it, of course, merely about aggrandizing self. Ministry is about our relationships (with individuals and with the congregation), and about giving out of our deepest self without giving ourselves away.
We will find it hard to give without giving ourselves away unless we have a strong prayer life. At the same time, we can find it hard to sustain a prayer life amid the demands of ministry. But for pastors it is the better part of valor to take the time for prayer and spiritual practice. A deep relationship with God helps us sustain relationships over time.