Loving those who love the gifts, but not the gift giver

Finding balance between meeting physical needs and spiritual needs can be quite tricky. There is a part of me that wants to do and give everything I can to help those who are in need. I can see myself giving up more in my life to help some of the endless needs of the poor. At the same time I can see how giving too much can be a hinderance to the gospel. The problem is that people become more interested in the gifts than God, the gift giver. I'm sure that some of the people that I am ministering to fall into that category.
Right now I am in the process of helping a few of my friends from the bridge who have few to no teeth in getting false teeth. Two of them seem to be genuinely excited about the Lord and are faithful in reading and learning the word of God. Another is clearly not, but he is a regular attender to the bible studies we provide. However, there are a couple of possible reasons for this. It could be that he is attending the bible studies because he feels obligated due to the help I have given him and his family. It is also possible that he could be thinking that a one hour bible study each week is a small price to pay in exchange for what he has already recieved and for the possibility of getting more stuff in the future.

Let me just say that I don't help people in the hopes that they will feel indebted to me. And I don't help people simply to create opportunities to share the gospel (However, I don't mind that meeting phyiscal needs does create opportunities). Actually, I can't help but to help the needy. God has made me in a way that I find great joy in helping them physically, but even more, spiritually. I often remember that I was spiritually dead, a needy sinner, underserving and desperatly in need of help. God mercifully reached out to me, forgave me, and helped an undeserving guy like me. With that reality ringing in my head and heart, I can't help but be moved and motivated to help others. I really do enjoy it.

I do what I can with the limited resources that God has given me to help the poor with their physical needs. More importantly, I always try to do the most loving thing that I could possibly do - I share with them the best thing that I have, Jesus Christ. If I merely feed them, give them clothes, medicine, an encouragement, I would be selfishly hording my greatest treasure for myself.
So how much giving of material things is too much? I believe that we should give enough to show love and meet desperate needs, but not so much that the reciever becomes focused on the gift rather than the gift giver (who ultimately is God). I imagine that having the right balance will be a life long challange. I also realize that there will always be some who will take advantage of me and who are not really sincere about Christ, but in the end, those who truly embrace Christ make it all worth it.