In a perfect world Christians would know what it means to be a Christian. But we do not live in a perfect world. I once heard Dr. John MacArthur discuss the issue of heresy saying that at no other time does the Church have the resources and the technology to reach every person in the world with the gospel. So what is Satan's ploy? Confuse the message of the gospel. As a result, we have few missionaries and many confused Christians fighting over what the gospel is.
Recently I sat down to read Greg Gilbert's book, What Is the Gospel? (9marks). Unfortunately this book is needed. There have been many other books on the subject of course. I would recommend books like The Gospel According to Jesus: What Is Authentic Faith? and similar titles, but such books are deep, detailed, and oftentimes a response to controversy. Gilbert's book, however, offers the reader a shorter and simpler understanding of the gospel beginning with God (His holiness, demand for justice, wrath, love, and mercy) and then moving on to discuss anthropology, Christ and the cross, repentance, the Kingdom, etc.
Gilbert accomplishes what he sets out to do. He explains the gospel to his reader. Gilbert uses the Bible and sound theology to lay out the gospel. The importance of this cannot be overlooked. If we do not understand the gospel, then we cannot do missions or call ourselves Christians. It is important for Christians to understand this message.
One of the things I really liked about this book was Gilbert's emphasis on issues like repentance (it means more than just saying, "oops, my bad!"), the kingdom of God (being both here and not yet), and a proper understanding of Christ (both fully divine and fully human). It is too easy for Reformed authors like Gilbert to just emphasize substitutionary atonement and leave other necessary aspects of the gospel out like the resurrection and repentance. Gilbert doesn't fall for that trap. He offers a fuller, complete understanding of the gospel.
One final comment on Gilbert theology. Substitutionary atonement, in Gilbert's assessment, is the gospel's understanding of the cross. To reject substitutionary atonement is to reject the gospel. But this does not mean that substitutionary atonement is the only application of the cross. Gilbert identifies three other applications: Christus Exemplar, Christus Victor, and reconciliation. Though these three are legitimate applications (see my series on Christus Exemplar), they are not the gospel. Propitiation is the gospel (in fact we will have a wrong understanding of these other applications without a right understanding of penal substitution).
For those who want to understand the gospel better, then I highly recommend this book. It is a short book and is a quick read. Gilbert isn't deep, difficult, or hard to read. Also, anyone wanting to know the gospel or confused on what the gospel is, I highly recommend this book. Once again Mark Dever and those at 9Marks Ministries have published another good book that Christians everywhere should read.
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