Living Christianity #6 - The Partial God

I have always had this question in my mind but never brought it up. It seems to be a bit of a taboo subject. I sometimes feel that if I thought this way, then my faith is very shallow and I'm indirectly saying that God is a bad God.
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"If a non-believer were to execute certain instructions written in the Bible, will he be blessed by those benefits associated with that said instruction, or are those blessings reserved for believers only?"
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For example. Tithing.

Malachi 3:10 "Bring all the tithes into the storehouse, That there may be food in My house, And try Me now in this," Says the Lord of hosts, "If I will not open for you the windows of heaven And pour out for you such blessing That there will not be room enough to receive it."
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So.
If a non-believer gives a tenth of his income to God, will he be blessed?
If a non-believer does not get blessed despite executing the wishes of God, it is reasonable to say that God is a partial God?
If that is true, then can it be reasonably said that God shows favoritism to certain people - i.e. believers?
Then if it is true that he shows favoritism to believers, then can it be said that the Bible is only applicable - in terms of rewards/benefits - to believers only?
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In many ways, I want to feel exclusive, to feel that I will be rewarded because I act in accordance to His instructions and because I love Him. I believe that I will feel a little jealousy if an unbeliever got blessed as well if he too does certain selective instructions as well. If that be the case, what's to stop anyone from picking and choosing what he/she wants to execute to get the corresponding rewards? Is my thinking warped? Any comments Bambi?