It's ALL God's money, He just asks you to return 10% of it back to Him. What your pastor and church does with it is on them. The principle on you is just to give it back. When you think it's your money and you begrudgingly give it back to the rightful owner, eventually He will take what He believes you owe. Just like the Jews spent 490 years in slavery because they didn't observe the Sabbath years on the land, there was a debt owed. Your giving is your business between you and God. If your church is pounding you for money, they are missing the whole point. God can give you money as well as give the church money if you don't give, but there are always consequences for not obeying God.
We have many in our church that choose not to take a tax deduction for various reasons. The truth is, if you give for a tax deduction, you give for the wrong reasons. Nobody knows what Cruz gives and to whom, but Cruz and God. Why should we even care? Works don't get you to heaven. We are created to do good works, but God should get the glory, not us. Trump might give millions to worthy causes, but if his relationship with God doesn't even involves asking blessing of his food, how close can he be to His Creator. When he meets God, he may brag about the giving he has done and God asks him, did it glorify me or you? When did you give me credit for the money I gave you?
One of the most telling phrases Trump has made was, "I haven't found the need to ask forgiveness for anything". That tells much more than a number on a 1040 form.
The forgiveness issue. I have heard some say that since they are saved by grace, there is no need as Christ already forgave you. I don’t quite see it that way.