On June 25, Timothy Keller delivered his last sermon as senior pastor of Redeemer Presbyterian Church in New York City. Not retiring, but taking a new step in his ministry, he will now focus on forming the next generation of pastors and leaders.

Dr. Keller is the founding pastor of Redeemer Presbyterian Church in Manhattan, which he started in 1989 with his wife, Kathy, and three young sons. For over 20 years he has led a diverse congregation of young professionals that has grown to a weekly attendance of over 5,000.

More than leading a growing number of Christians in the City, Tim Keller has explored Christianity at its core. He and his Church have been examples of true and uncompromising love for the urban communities, and especially for those who thought themselves so far from the Church. They have embodied a new model of the first commandment "Love your neighbor as yourself" where Christianity was said to be dying - among the urban working class.

What I really learned from Keller's ministry is listening. I admire the gentleness, patience and love he has towards all, no matter how rich, poor, highly educated, or from a more modest education, he listens and truly addresses issues and concern about Christianity. He answers in truth and never compromises the Gospel, but he never rejects or avoids a question.

His biggest contribution to Christianity around the world is without question his prolific writing.Tim Keller is Chairman of Redeemer City to City, which starts new churches in New York and other global cities, and publishes books and resources for faith in an urban culture. In over ten years they have helped to launch over 250 churches in 48 cities. More recently, Dr. Keller’s books, including the New York Times bestselling The Reason for God and The Prodigal God, have sold over 1 million copies and been translated into 15 languages.

Growing up in France where I encounter few contemporary Christian apologists, reading "The Reason for God" in my mother tongue was life changing. I really thought he was the C.S. Lewis of our time. He answered my questions and the questions of my neighbors and friends willing to be objective and fair. Never judging the unbelief, Keller on the contrary works with and from it.

This summer, my Church's student group and I are going through a detailed study of "The Reason for God." Future scientists, lawyers, teachers, doctors, or musicians have different questions for Christianity. However, we all share the need to understand sin and redemption at a deeper level. Why is Jesus still the only way when modern societies tell us that we should be compromising or searching elsewhere?

This summer, if you have a little bit of free time left, pick up a Tim Keller book, and find out! (you can also listen to free sermons on Youtube!)

Check out: The Prodigal God, Encounters with Jesus, The Freedom of Self Forgetfulness and The Meaning of Marriage.