There are a few men whom I love for the clarity and emphasis on the centrality of the gospel in the lives of believers. These include Tim Keller, Jerry Bridges, C.J. Mahaney, and Jay Wetger. Most have probably heard of the first 3. I found Jay Wetger through an OPC church I used to visit. He is great at applying the gospel to our lives. I have only read a handful of his articles, but they have all been sweet. Check out 'Gospel Reasoning', 'The Doctrine of Justification by Faith: Understanding So Great a Salvation', and 'The Cross-Centered Life.' If you do not have the habit of preaching the gospel to yourself, treat yourself with these brief articles.