“…that Scripture in Jude is a most remarkable one. In the 14th verse onwards, it is said, ‘That the Lord comes with ten thousands of his saints, to execute judgement upon all, and to convince all that are ungodly among them, of all their ungodly deeds, which they have ungodly committed, and of all their hard speeches, which ungodly sinners have spoken against him’. Mark here in this 15th verse mention is made four times of ungodly ones: all that are ungodly among them, all their ungodly deeds which they have ungodly committed, and of all their hard speeches which ungodly sinners have spoken against him.
This is in general, but now he comes in particular to show who these are: ‘These are,’ he says, ‘murmurers’ — that is the very first. Would you know who are ungodly men, whom God when he comes with ten thousand of angels shall come to punish for all their ungodly deeds that they do, and those that speak ungodly things against him? These ungodly ones are murmurers; murmurers in Scripture are put in the forefront of ungodly ones, and it is a most dreadful Scripture, that the Lord, when he speaks of ungodly ones, puts murmurers in the very forefront of all.
You had need to look to your spirits; you may see that this murmuring, which is the vice contrary to this contentment, is not as small a matter as you think. You think you are not as ungodly as others, because you do not swear and drink as others do, but you may be ungodly in murmuring.”
-Jeremiah Burroughs, The Rare Jewel of Christian Contentment, 138-139.