After exhorting the oppressed believers to be patient until the coming of the Lord, James calls them next to "not complain against one another...so that [they] will not be judged." The root word for "complain" means to groan or to sigh, which in this context means much more than the mere disappointment expressed upon some inconvenience. This call to not grumble has to do with a problem stemming from a heart attitude that is not pleasing to the Lord, as it speaks of a heart that disregards the sovereignty of God and doubts His purposes.
Ponder on Philippians 4:10-13. There, as the apostle Paul himself had to LEARN to be content, it is evident that while still in the flesh, we have the tendency to grumble. By God's grace, though, we can learn like the apostle Paul "how to be brought low" and "how to abound in any and every circumstance." The same Spirit that enabled Paul is able to help us be content as we yield ourselves to His control.
Again, James points the believers to the soon coming of Christ as his basis for exhorting them to not complain. "[Behold], the Judge is standing at the door." As an example, James reminds them about "the prophets who spoke in the name of the Lord." Note how that in the O.T, the prophets had to rebuke God's people and they were ill treated! Nevertheless, the prophets faithfully delivered God's message. In Hebrews 11, we are given the testimonies of those who suffered and patiently endured for the sake of Christ. By God's grace, it can be done!
As a more specific example, James calls the believers to consider the "steadfastness of Job." James points out how they have seen "Job’s perseverance and… what the Lord finally brought about. The Lord is full of compassion and mercy." Job's every trial and every tear was under the sovereign purposes of the Lord!
Finally, God calls the believers to treat God's name with respect and to be truthful. "Say only 'Yes' when you mean yes, and 'No' when you mean no, and then you will not come under God's judgment." Why this exhortation? Because in the midst of trial or oppression, there is the real temptation of using God's name in vain for our own ends or of lying to get out of situations we should, instead, face with steadfastness.
In brief, as we are assured of the unchanging character of the Lord God who is compassionate and merciful, we must, by His grace, patiently endure! We are to persevere in truth; and, we are to do so without grumbling - for His glory. Hard? Absolutely. Impossible? No. As has been made plain in Scripture, the Spirit of God indwells every believer; and, if you as God's child have His Spirit, then with God, nothing is impossible! Step by step, let us, therefore, start learning. Let's learn to patiently endure without grumbling, for "godliness with contentment is great gain" (1 Tim. 6:6).
