How much is too much?

So I have been wrestling with the subject of generosity a lot lately.  I feel like God is really challenging me so much in this area.  And to say that I have been "wrestling" with it is exactly how it feels.  God's Word is pretty clear that we who have much are called to give generously and help in meeting the needs of the poor.  There is no question that I believe that to my core.
The other morning I was reading in Luke 12, a familiar scripture, and was struck once again by this call to give.

²⁹ And do not set your heart on what you will eat or drink; do not worry about it. ³⁰ For the pagan world runs after all such things, and your Father knows that you need them. ³¹ But seek his kingdom, and these things will be given to you as well. ³² “Do not be afraid, little flock, for your Father has been pleased to give you the kingdom. ³³ Sell your possessions and give to the poor. Provide purses for yourselves that will not wear out, a treasure in heaven that will never fail, where no thief comes near and no moth destroys. ³⁴ For where your treasure is, there your heart will be also.

These are some powerful words!  I was so struck by the way that this scripture ties together worry and giving.  Maybe I had never really thought very much about the connections between the two before.  But isn't it true that when we are worried about our own needs, what we will eat or wear, we are much less likely to give to meet the needs of someone else.  What a challenge this is for me!  As a missionary, it can be tough sometimes being "dependent" upon financial support from others to meet my needs and the needs of my family.  The reality is that we are dependent on God for everything but it is hard to have that pass through other people's hands.  I can easily find myself feeling worried about how we will have enough money to do what God has put in our hearts.  On the other hand, at the same time, I easily find myself feeling guilty for needing financial support and often wonder if I am worthy of it or doing enough to "earn" what we are given.  
Missionaries are faced with many questions and decisions when coming to a new culture to live.  I struggle with these issues on a daily basis.  How much is too much?  What is okay for me to buy and what isn't?  What standard of living is God calling me to? How much do I give?  Can I give too much that it can actually hurt people in the long run?  These are tough things.  When you are living and ministering in a Third World country, faced with poverty daily, how do I choose to live?  In light of the Gospel, how much is too much?   
I will never forget the first time I posted pictures of our new house online.  I can remember feeling like people in America were probably expecting to see a little mud brick hut and would be surprised to see that we have a relatively large, beautiful, brick house.  I sort of remember wondering if people thought that I should be living in a hut instead.  Maybe that would somehow be more "spiritual" as a missionary?
God has been really challenging me to understand and look at these issues as a matter of my heart.  The scripture says that where your treasure is, there your heart will be also.  Where is my treasure?  Is it in having a nice home or good food to eat? Am I setting my heart or what I will eat or drink, like this scripture says?  Or am I seeking first the Kingdom regardless of how much or how little I have from day to day.  
There is a lot to think about and wrestle with on in this area of things and giving.  Because this post is getting long, I will continue to write about these things and what God is teaching me over the next few days/week.  I want to encourage you and challenge you to let God examine your heart as I let Him examine mine.