If the best way to understand the Christian faith is to read the Gospels, then it follows that the next most important books will be those that help us better understand those Gospels.
Noticing this need in his own congregation, J. C. Ryle wrote his Expository Thoughts on the Gospels, which have spread throughout the world for over a century, without their popularity or usefulness diminishing.
Ryle's clear and direct words are also a great encouragement to read the Bible. While his primary goal is to help the reader know Christ, he also has another idea in mind: he writes in such a way that his commentary on Luke can be read aloud to others.
Unlike many authors, his work is just as good when heard as when read. There are many other more extensive commentaries on the Gospels, but none are as fascinating to listen to, whether with family, in groups, or over the radio, as those by J. C. Ryle.