Hello Aaron,
I've found this discussion quite interesting, although it does sadden me when discussions devolve into ad hominem attacks. I must confess that I too assumed you were perhaps a teenager. I suppose the combination of the SpongeBob avatar, the word "Disney" and the somewhat immature tone of some of you posts caused me to jump to this conclusion. I do not say this as an attempt to insult you; only to say that I too reached the wrong conclusion (and for that I apologize).
I would like to address two points which you've been making. The first is your continuous use of the phrase "rob God". I assume that your use of this phrase is based on Malachi 3:8-12. If that is the case, I'd like to point something out:
The Israelites of the time period that Malachi was written paid three tithes. The first, which was paid yearly, was to support the Levites (Lev. 27:30, Num. 18:21) since they had no land of their own. Here's an interesting article about this:
http://home.earthlink.net/~russkellyphd/id26.html
The second tithe, which was paid yearly, was to pay for the various religious festivals (Deut. 12:4-7, 14:22-27).
The third tithe, which was paid every three years, was for the poor (widows, orphans, aliens, etc. - Deut. 14:28, 26:12).
This averages out to 23.3% per year total.
The question then is, which tithe is Malachi talking about? All you have to do is go up a couple of verses to 3:5 - "So I will come near to you for judgment. I will be quick to testify against sorcerers, adulterers and perjurers, against those who defraud laborers of their wages, who oppress the widows and the fatherless, and deprive aliens of justice, but do not fear me". This is consistent with the rest of scripture. There are hundreds of verses throughout the Old and New Testaments which express God's concern for the poor and marginalized. In fact, it is one of the most constant themes throughout the Bible.
So let me ask you. Do you rob God? Does your tithe go to the poor? Or does it go to pay for a church building and a pastor's salary? Can you account for how your tithe is spent or do you just drop it in the collection and give it no further thought?
On another point, Abram did indeed give to Melchizedek, the king of Salem, a tenth of the war-spoils he received by defeating Kedorloamer and the other kings of Sodom. This was, and still is, a very common practice in the Middle-East. A local ruler will pay a tribute to an allied ruler in order to maintain a peaceful, cooperative relationship. To equate the tribal leader Abram's one-time tribute given to an ancient regional priest/king to your putting 10% of your income in the plate at church every Sunday is a fantastic leap.