Tim Keller is a very complicated person theologically, so please bear with me as I explain. I am a big fan of Keller's Christ-centeredness and clear explanation of the gospel. In fact, Keller's presentation of the gospel is one of the finest we have ever heard. His understanding of Grace alone in Christ alone from a Reformed standpoint is truly superb... often profound. He loudly proclaims that "the gospel is NOT what we do for Christ but about what Christ has done for us" which is about as far away from RCC and the emergent movement as one could imagine. I have personally been blessed greatly by his ministry. We promote him because his teaching overall is VERY good.
But I have always been a critical fan of Tim Keller. Let me explain. On the one hand he loves Jonathan Edwards and the Puritans, Calvinistic experientialism and the gospel grace alone in Christ alone. On the other hand he does integrate some ideas from outside the reformed tradition. That is not always a bad thing since we can learn from other traditions. However, in this case I would take sharp issue with a few of his positions. 1) He is a theistic evolutionist. 2) He sometimes tends to have an imbalanced over-emphasis on social justice & cultural renewal (which has led many local churches influenced by him to delve unconfortably into left or right wing politics, which "wing" depending on the location of the church). And (3) it has recently come to my attention that his church practices contemplative prayer/Catholic mysticism, which could potentially lead people to embrace the harmful counter-Reformation teachings of Ignatius Loyola, Saint John of the Cross, Saint Teresa of Ávila (Catholic mystics) who teach (among other things) the extra-biblical ideas of Christian perfection, visions, and mystical divine guidance. In my view some of these accommodations tend to be inconsistent with the gospel he otherwise so powerfully communicates.
So a word of caution to young Christians getting overly excited about his material. (I love RUF and the PCA so don't get me wrong here but) there is a trend of an almost cult following among a number of RUF ministers and other young men coming into the PCA right now. This could potentially be an unhealthy thing. I just want readers to step back for a second and take these things into account before wholeheartedly diving in. Again, his books on idolatry, marriage, apologetics and especially his books on the gospel etc. are usually very helpful and that is why we carry them without reservation. I love his Christ-centeredness, his experiential emphasis and I think he communicates things in a very helpful way, but I take sharp exception to his theistic evolution, his ecumenism and his sometimes imbalanced emphasis on social justice. And we would never consciously carry or promote any resources which specificially promoted these erroneous ideas or practices.
We can disagree with a man on many things and still think that people can benefit immensely from his gospel ministry. I know there is a group of people would prefer that we remove him altogether from our store. And I thank them for bringing some of these things to my attention. But after having sought counsel on this from other pastors I feel a warning of this kind is best way to to go forward. If these warnings are taken into account and heeded, then I believe you will be blessed by Dr. Keller's helpful ministry.