Our works, which may be called good, are only such as God has commanded in his word, and not those which are devised by men out of blind zeal, or upon any pretense of good intention (WCF 16.1).

Here is a man who is vigorous in the pursuit of his religion. He is zealous in chasing after God. Those who know with full assurance that they are going to heaven continually press forward and toward it.