I just read an article, A Lesson from Spurgeon on Evangelism, by Tom Ascol. Let me encourage you to read the whole article. In part Ascol writes:
Any study of his ministry immediately reveals a man obsessed with evangelism. From the moment of his conversion to his dying day, Spurgeon maintained a deep burden for souls. He was a fanatic about it–in all of the right ways. As a pastor he took to heart the apostolic injunction to “do the work of an evangelist.” And he diligently tried to stir up evangelistic concern among his church and fellow preachers.
This fact confounds some students of Spurgeon’s life. For, along with his evangelistic fervor (and, we might add, despite modern claims to the contrary), he never wavered from a strong commitment to the doctrines of grace. He clearly understood, personally believed, and powerfully proclaimed what is popularly called “Calvinism.” And he did so not out of any kind of devotion to a man or philosophical system, but because he was convinced that the body of truth which historically flew under that banner was nothing other than biblical Christianity. It was this understanding which enabled him to preach Christ so simply and persuasively.
Some who disagree with Spurgeon’s theology but appreciate his evangelism have difficulty reconciling his beliefs with his practice. Their reasoning typically goes like this: “Yes, Spurgeon was a Calvinist, but despite that fact, he was evangelistic.” Such an analysis, however, completely misses the mark. It would be far more accurate to say that “Of course Spurgeon was a Calvinist, and therefore he was evangelistic.” His devotion grew out of his doctrine and his belief gave direction to his practice.