It appears that you took what I said the wrong way.
I am not advocating a tax increase for Christians.
Christians who believe what the Bible says about being blessed by God (according to Malachi) and gave expecting a deduction were giving for the wrong reason in the first place. Getting God’s blessing for donating money, paying tithes, offering and so on (which churches keep a record of for deductions) should have been the only reason they were giving to the church.
I hope it doesn’t come down to churches losing tax exempt status, but if it does happen and donations drop then we will see the Mammon-serving Christians being exposed for the rest of the church to see: the ones who gave not wanting any tax deductions, but only gave being convinced that God’s blessing was more than enough...
I have prepared more than 10,000 tax returns over 30+ years. I can safely say that those who tithe do so without concern about income tax. I can also say those who do not tithe don’t think about tax savings until they file return and then want to claim what they did not actually pay. The effect of your proposal is a tax increase on Christians which is something I find offensive. You want to extend it to all charity to be fair then okay.