I pointed this passage out to a pastor once. He wasn't impressed. If one wanted to be literal, one could argue that since the original poster (presumably) celebrates Thanksgiving, Christmas and Easter, that covers the feasts. Your taxes fund welfare which takes care of the poor. If you give 3-4% of gross to your church, that should cover the rest.
On the other hand
Luke 6 38
Give, and it will be given to you. A good measure, pressed down, shaken together and running over, will be poured into your lap. For with the measure you use, it will be measured to you."
So the question you might want to ask is, how much do you want to get back?
Of course he wasn't. Even pastors succumb to greed sometimes. On top of that, they have replace the biblical feasts (passover, etc.) w/ paganized x-ian feasts like Easter/Ishtar and Christmas/Mirthra day so it's not surprising they would make up their own interpretation of HaShem's word about the tithe as well.