As a training specialist with the U.S. Dept. of Agriculture, I conducted a course for managers called “Dealing with Difficult People.” It was always well-attended! As you know, it's not just a workplace problem—all relationships can be hard at some time.
The workplace training put emphasis on the “difficult person" and very little on the manager’s attitude or feelings toward that person. Why? because it’s easier to focus on someone else’s problems than to take responsibility for your own. Jesus (who dealt with lots of difficult people) confronted that attitude when He said: “why worry about a speck in your friend's eye when you have a log in your own? How can you think of saying, `Friend, let me help you get rid of that speck in your eye,' when you can't see past the log in your own eye? Hypocrite! First get rid of the log from your own eye; then perhaps you will see well enough to deal with the speck in your friend's eye. (Lk. 6:41-42 NLT).
Before you can even begin ‘dealing’ with a person who may be difficult for you, you must ask God WHY He put the person in your life. Don’t presume God has engaged you to be His “agent of change” for that person. It may be God has employed that person to be His “agent of change” for you! Through your negative reaction to that person, God is revealing your need for change—for “heart surgery”—to fashion in you a heart of love, compassion, kindness, and forbearance (Col. 3:10-12).
As you cultivate God’s perspective (seeing through His eyes) He will guard you from a critical spirit. When you look at yourself first (Gal 6:2) and on what God is doing in your heart, the more humbly you will approach the weaknesses of others. Only then are you qualified to be God’s “agent of change.”