J.I. Packer has served as a professor of theology at Regent College in Vancouver, Canada for a number of years. He has been known for a number of years for his powerful books. In January of 2016, he announced that his ministry would significantly decrease because he is losing his eyesight (to read a humbling interview with Packer on losing his eyesight, click here).
While he has written a number of books, he is best known for his work Knowing God. You might also consider Evangelism & the Sovereignty of God, Growing in Christ, or his Concise Theology (but know that he writes from a Reformed and Anglican perspective). To learn more about J.I. Packer I would recommend Leland Ryken’s book J.I. Packer: An Evangelical Life.