what is my reward?

Matthew 6:2-4

The key phrases in this passage are: "they have received their reward in full" and "Then your Father, who sees what is done in secret, will reward you." These two phrases will be repeated through out this section. The key word in this passage is "hypocrite" which will also be repeated, always in terms of "don't be like the hypocrites."
Jesus is giving an example of how not to do acts of righteousness to be seen by others. Again, the point is not that we should never be seen to be giving to the needy but our motivation must not be to receive praise from people. Jesus lays it out as a choice: either you can give to the needy to be rewarded by humans or you can give to the needy to be rewarded by the Father. It is a rhetorical choice because the reward that the Father gives is going to be much greater than the praise of other humans. I believe that Jesus is using hyperbole here when he says to not let your left hand know what your right hand is doing. This is consistent with his hyperbole in the previous section when it comes to cutting of a hand or plucking out an eye. He seems to use it to emphasize his point. He is probably using hyperbole as well to describe the giving of the hypocrites. I would have to study the history and practice of that time to know for sure if they actually formed a brass band to precede them as they were on their way to give to the needy.
Here is what I can apply from this passage: First, giving is expected. Jesus does not say to stop giving to the needy but assumes that we will be giving to the needy (v. 2 "when you give..."). I think some people need to hear this message and I know that I need to be reminded constantly. Jesus expects that one of his disciples will make it part of his normal life to give to the needy. Second, this is more about motivation than about secrecy. If my goal is to bring pleasure to my Father then it is not ruined if someone sees me giving and points it out. I've heard of a pastor in the middle of building campaign announcing to his congregation what his pledge was, not to be seen as righteous but to challenge his congregation to be sacrificial in their giving as well. At our church, we made it a bit more anonymous and announced what the leaders had pledged as a total. Thirdly, it is not wrong to be motivated by reward. Jesus clearly teaches that we will be rewarded but we must choose whom we wish to be rewarded by. I can earn the praise of humans, have my name on wings of hospitals or universities (assuming I had enough money to buy the right to have my name there) or I can earn the pleasure of God and have my name written in his book. This teaching does cause me some problems because I believe that we can't earn God's favour but we are given his favour and pleasure by his grace through faith in Christ. So Jesus is not teaching that if you give in secret you are somehow more righteous or that you can earn salvation. But he is teaching that we will be rewarded. The main point is that we must choose whom we want to reward us.