"Hoarded Wealth In The Last Days"

Hoarding wealth by not paying workers--either by not paying them at all or by incompletely paying them, such as by not giving them livable wages that are also proportioned to the task and their skill--is indeed a form of theft, of degradation, and of arrogance.  The Old Testament prescribes precise ratios of restitution for various cases of theft in Mosaic Law (see Exodus 22), adding that people should also pay poor and desperate physical laborers before night arrives (Deuteronomy 24:14-15), and that those who go unpaid might cry out to God in their distress and unjust treatment.  To do otherwise would be sinful and this would not change over history as so many pretend the moral tenets of Yahweh do.

Instead of simply giving their own laborers their deserved compensation at some unspecified, arbitrary, or shifting future point in time, employers are to do so immediately, as Mosaic Law very clearly says to provide compensation before sunset, not up to two weeks later in accordance with American payroll norms.  Of course, not receiving just payment is even worse than a delay in receiving compensation or in being paid at unfairly low rates.  The book of James alludes to Deuteronomy 24:14-15 when it speaks of rich people who exploit their workers by failing to pay their wages (5:1, 4)

The New Testament condemns those among the rich (and no one is arrogant, classist, or willing to steal just because they are rich) who sinfully stockpile wealth by not paying their own workers who have already completed services for them.  Their gold and silver corrodes (5:3), which will serve as testimony against them in the cosmic judgment after the resurrection of the dead.  By saying such people are hoarders of wealth in the last days (5:3, 5-6), James points out the added stupidity of living for greed as the judgment of the dead draws nearer and nearer.

This is not an idea derived from liberal emotionalism and distortion of the Bible, but it is the actual Biblical doctrine that itself depends on other doctrines established in the Torah and beyond.  No one is evil or irrationalistic because they are rich (and modern liberalism is obviously invalid on this front).  That does not logically follow.  Regardless, the rich who choose to life for assumptions, selfishness, and classism would practically always be harder to withstand than the irrationalists who do not have the same material wealth.  They would also be the kind of person who would not care about logical necessities, the very possibility of them being in the wrong, or the genuine evidence that Christianity with all that it entails, the condemnation of unjust hoarders of wealth included, is true.

One could have great wealth obtained through legitimate means, such as the incidental discovery of natural resources or the non-predatory operations of a business, and serve Yahweh.  What one could not do is deprive others of that which they have rightly earned and still serve the deity of Christianity.  The oppressors of James 5's early verses are exactly the kind of person who cannot serve both God and money (Matthew 6:24).  Thinking themselves worthy or at least safe from any conflict with ultimate reality, they have really made themselves, as James says, like a fattened calf in the eschatological "day of slaughter."