It's far easier for someone who makes $21 million a year to give 14% of his income away than it is for someone making $20,000 a year. It's far easier for someone to afford gas, groceries, and paying the utilities when those bills take up a far smaller part of your paycheck. I personally am not able to give away that much. But if I made $21 million, I'd definitely give away a lot of that. I could only use so much money before I felt like I didn't need any more. If I made $4 million and gave away $3 million to charity, then that would be far more generous than a multimillionaire giving away the same amount.
Christian apologetics is the art of rolling a dog turd in sugar and selling it as a donut.