In the first verse of Job 1, Job is spoken of as "blameless" in the ESV and other modern translations - and "perfect" in the KJV, ASV, etc. In John Calvin's sermon on this verse, he discusses this description.
"It is said, that he was a sound man. This word sound in the scripture is taken for a plainness, where there is no point of feigning, conterfeigning, or hypocrisy in a man, but that he sheweth himself the same outwardly as he is inwardly, and specially when he has no starting holes to shift himself from God, but layeth open his heart, and all his thoughts and affections, so as he desireth nothing but to consecrate and dedicate himself wholly unto God. The said word has also been translated perfect, as well by the Greeks as by the Latins. But for as much as the word perfect, hath afterward been misconstrued, it is much better for us to use the word sound. For many ignorant persons, not knowing how the said perfection is to be taken have thought thus: 'Behold here a man that is called perfect, and therefore it followeth, that it is possible for us to have perfection in ourselves, even during the time that we walk in this present life. But they deface the grace of God, whereof we have need continually. For even they that have lived most uprightly must have recourse to God's mercy, and except their sins be forgiven them, and that God uphold them, they must needs all perish. So then, although they which have wrested it to a contrary sense, (as I have said), let us keep still the word sound. Then look upon Job, who is called sound. And how for? It is because there was no hypocrisy nor dissimulation, nor any doubleness of heart in him. (p. 3, Sermons on Job, Banner of Truth)
Plainly spoken, but that is how it must be. Our claims of a desire to serve God wholly fall apart if we have not the soundness of Job in us. I was reading this morning in Luke, and came across the statement by Christ to the Pharisees that He came for the sinner, and not for the righteous. Pretentious righteousness fails the test of soundness. Job presented himself as he was - a sinner in need of grace. This he coupled with an uprightness, which also according to Job 1:1 describes him, in a truthful presentation to the world of who he was. No hypocrisy there - only a plainness of walk before God and before the world that we all must strive for.