John received his undergraduate degree in theater from California Polytechnic University (Pomona) and his MA in biblical counseling from Colorado Christian University under the direction of Dr. Larry Crabb and Dr. Dan Allender. Prior to joining Focus on the Family in 1988, John served for five years on the staff of Sierra Madre Congregational Church in Southern California.

In July 2000, John left Focus on the Family, where he had worked for 12 years, to launch Ransomed Heart Ministries. John travels extensively in the U.S. and abroad. John, his wife, Stasi, and their three sons live in Colorado Springs, Colorado. In addition to publishing many books, he has produced three videos: Risky Business: A Look at Gambling, Whatever Happened to Marriage?: A Look at Divorce, and Created Different?: A Look at Homosexuality.

A fundamental tenet of Eldredge's theology is that men and women possess the Imago Dei — they are created in the image of God. For him, on the basis of Genesis 1:27, the core of what it means to be image-bearers is found in gender. God intentionally created mankind as male and female, placing different aspects of His character into each, so that the full expression of His glory is seen when the two are joined in marriage. Therefore, the rescuing of the heart of both masculinity and femininity is indispensable to Eldredge's ministry.

Eldredge says of himself, "I’m 55. I live in Colorado Springs, Colorado. My wife Stasi and I have three sons. My graduate degree is in counseling. Professionally, I’m a Writer and a speaker. I don’t pastor. I’m not a preacher. I don’t have a church that I lead."