What advice would you give fellow workers in the ministry?
First, maintain your devotional life. Nothing else can take its place. Nothing in your life will become meaningfully significant before God if you neglect it. It's the hardest discipline, but if that dies, the ministry is dying.
Second, pray. If you are a praying Christian, your faith will carry you. If you are not praying, you will have to carry your faith - and it will exhaust you. It is in the season of prayer that God makes you into his dream.
Third, stay humble. One of Billy Graham's great strengths is his obvious sense of humility. Success in ministry can be quickly stifled if that is not kept in perspective.
Fourth, become a disciplined reader. The problem in our communication today is that we can become shallow, limited and sterile if we are not willing to read sufficiently. Find authors who have something to say, and master what they are saying. A good author will generally introduce you to a variety of other good authors. The worth of a book is determined not only by what it says, but infinitely more by what it points to beyond itself. In a number of volumes I have, the footnotes are underlined more than the texts themselves. Immediately they tell you who has shaped the writer's thinking, and which works have inspired or coalesced in the writer's mind.
Fifth, be very close and affectionate to your family. My wife and my children know they are the four most important people in my life. Especially in the itinerant life, it's easy to forget the greater importance of your relationship with members of your own family. Keep that close, and it will keep you real.