Genesis 28: Bethel

Then Jacob made a vow, saying, “If God will be with me and will watch over me on this journey I am taking and will give me food to eat and clothes to wear so that I return safely to my father’s house, then the LORD will be my God and this stone that I have set up as a pillar will be God’s house, and of all that you give me I will give you a tenth.” -Gen. 28:20-22

Some of us need an experience akin to that which Jacob experienced at Bethel in order to have the right understanding of who gives and who gets.  Perhaps we're so blind that unless the heavens open up and we see the angels ascending and descending, we think that we own or control this world we inhabit.  All of our scheming and plotting, our earning and investing, our buying and hoarding separates us from, rather than drawing us closer, to our source.  When we realize just how much God has given us,  our response can be nothing less than giving back.  A tenth of our earnings seems to be a paltry sum compared to what we have been given.