K.P. Yohannan on giving to missions:

...a word of caution.  Do not look for a reason for not giving to the work of God.  Remember, we must give all we can, keeping only enough to meet our needs so the Gospel can be preached before "...the night cometh, when no man can work" (John 9:4).  The problem for most is not that we give too much, but that we give too little.  We live selfishly and store up treasures on this earth that will be destroyed soon, while precious souls die and go to hell.