People who no longer believe LDS doctrine SHOULD be challenged upfront to be honest and decide whether they want to continue to be members or not. My position is that LDS doctrine is true, that the leaders are called of God and inspired, but that they make mistakes, don't know everything, and that the CULTURE of the church, regarding proper scriptural based calculation of tithing, is poisoned by laziness and ignorance.
I brought up Genesis 14:39 in my ward's elder's quorum meeting (the lesson topic was tithing) and got more hostile opposition than you can shake a stick at (because the culture, not the doctrine, but the culture of the church is absolutely poisoned with ignorance). Yep, for bringing up a SCRIPTURE. I tried to cause honest discussion of that scripture, which is HUGELY problematic for the true teachers of false doctrine in the LDS church (i.e. lazy cultural followers) because:
1. Genesis 14:39 was restored by Joseph Smith the prophet, making it superior scripture to LDS believers, on par with the Book of Mormon and the Doctrine and Covenants.
2. Genesis 14:39 is clear as a bell and requires no interpretation, although I recently had a member of my stake presidency pretend it's not clear, and in disturbingly hostile fashion, refused to tell me HIS interpretation. This guy is ordinarily very well informed scripturally and ordinarily has a good spirit about him. This just goes to show the sheer power of the corruption of the CULTURE of the church.
3. The shallow people who evade real discussion on this issue can't say I'm preaching false doctrine because I'm using their own scriptures. D & C 119 is a big help too because the word "interest" is used, and interest ONLY means new wealth, not necessities.
I have come to the sad conclusion that the only way to send a message to church leaders to finally deal with this issue and fix the cultural habit of the church (which pushes people to "income tax" their tithing) is to encourage people to stop paying most tithing. Reduce your tithing payments 90%. Totally stopping paying tithing plays into the hands of the church leaders we're trying to communicate with, and gives them an "out" on the issue. Most LDS members have paid far too much in tithing for a long time anyway.
FACT: a line from the "Gospel Principles" book has thankfully been removed, which only the president of the church could have authorized. A line that USED TO tell people to tithe everything, and boy I mean everything, and to do it first. That garbage line is gone (it was false doctrine).