For His own reasons, the Lord provides answers to some questions, with pieces placed here and there throughout the scriptures. We are to find them; we are to earn them. In that way sacred things are hidden from the insincere.
It is dangerous to be sincere unless you are also stupid.
It is in vain to try to hide a bad spirit from the eyes of them who are spiritual for it will shewe itself in speaking & in writing as well as all our other conduct, it is also useless to mak[e] great pretentions when the heart is not right before God, for God looks at the heart, and where the heart is not right the Lord will expose it to the view of his faithful saints.
Tithing is one of these tests. Speaking of this, President Stephen L. Richards, former member of the Quorum of the Twelve and First Presidency, stated: “I feel certain that it is not only the test, the acid test, of true loyalty and devotion, but that it is likewise the greatest of the developers of true spiritual allegiance. It has been said that you can tell what a man thinks of a cause by the way he puts his money into it. Talk is cheap. It has never caused any particular wear and tear upon the jaw and they say that the tongue is the only organ of the body that never gives out, so that all our protestations by word of mouth are easily given, but when a man puts his hand down in his pocket and takes out the hard-earned money that comes from his labor, and devotes that to the establishment of a cause, you know without further evidence that he is sincere”