Elihu exhibits righteous indignation against Job, because when Job is in trouble he doubts his God; and against the friends, because, being bigots, they make up their own mind, and fail to help Job pastorally. Though they have wonderful words, yet they are just out to win their point.
Elihu’s great point is that the trials that Job has suffered are not to be seen as punishment but as discipline. This makes all the difference because, although the pain may be the same in both cases, God’s motivation is very different and the end he has in view is totally different. We can bear with something that is unpleasant if we know it is working for our good. This is the argument of the book of Hebrews in chapter 12. What makes us able to willingly submit to grievous things is that ‘afterward it yields the peaceable fruit of righteousness to those who have been trained by it’.