And I tell you, make friends for yourselves by means of unrighteous wealth, so that when it fails they may receive you into the eternal dwellings. Luke 16:9 English Standard Version (ESV)
Make to yourselves friends. Christ…teaches us that by acts of charity we obtain favor with God, who has promised, that to the merciful he will show himself merciful, (Psalm 18:25.)…
The Lord looks not to the persons, but to the work itself, so that our liberality, though it may happen to be exercised towards ungrateful men, will be of [benefit] to us in the sight of God. […The depravity of men does not prevent the Lord from placing on his records all that we have expended on the poor.]
…Our kindness to the poor will be a seasonable relief to us; for whatever any man may have generously bestowed on his neighbors the Lord acknowledges as if it had been done to himself.
Calvin’s explanation makes me reconsider the make-up of my own giving.
To the parts I did understand, Calvin says:
When you fail. By this word he expresses [our] time of death, and reminds us that the time of our administration [of riches] will be short, lest the confident expectation of a longer…life should make us take a firmer grasp. …Many squander what they have on superfluities; while others…deprive both themselves and others of the benefit…
Of the mammon of unrighteousness. By giving this name to riches…Christ justly represents them as worthy of our suspicion; just as on another occasion he called them thorns, (Matthew 13:7, 22.)
[…Christ intends, by way of an unstated contrast,] that riches, which otherwise, in consequence of wicked abuse, polluted their possessors, and are almost in every [case] allurements of sin, ought to be directed to a contrary object, to be the means of procuring favor for us. [This is] a warning given to believers to keep themselves free from unrighteousness.
Key to the right use of riches, then, is to neither squander nor hoard; using it not as an occasion for sin but, instead, for righteousness.
Clarifying what our attitude should be when giving, the Apostle Paul cautions:
The point is this: whoever sows sparingly will also reap sparingly, and whoever sows bountifully will also reap bountifully. Each one must give as he has decided in his heart, not reluctantly or under compulsion, for God loves a cheerful giver. 2 Corinthians 9:6-7 (ESV)
And we do well to remember that time really is money when it comes to charity:
You shall not see your brother’s donkey or his ox fallen down by the way and ignore them. You shall help him to lift them up again. Deuteronomy 22:4 (ESV)
Deeds of Christian Charity, 1575, Pieter Aertsen (circa 1508–1575), in the public domain in the United States