Preachers often quote Spurgeon today because he had an ability to explain Christian truth to ordinary people with pointed, memorable statements. The people who heard and read his words were effectively taught theology and enjoyed it. He was a dogged defender of the Bible as God's truth.
There was another side to Spurgeon's character - a sensitive and loving nature that spurred his preaching of the gospel. Spurgeon realised that he could influence the church beyond his own lifetime if he could encourage future pastors to trust the Bible, love people and preach the truth fearlessly. To achieve this he collected his lectures to his students and published this book. It has been a classic of pastoral theology ever since and is still used to train ministers to this day.