Matthew 6:1-4

Practicing righteousness.
v.1 Good deeds (practicing your righteousness, i.e., religious observance) include giving (2-4), prayer (5-15), and fasting (16-18). This verse warns about doing such deeds to be seen by men. We of course are to do such things (5:16), but God knows the motive of the heart. Do them in secret and your reward will come from God in heaven. The reward may perhaps be spiritual maturity in this life, or a heavenly reward in the life to come (or likely both). We certainly want to be characterized by righteousness (Ps 1) and we want others to see that in our life (5:16), but here we are talking about religious duties. Those in religious ministry must not value the praise and pay of their congregation over what God has called them to do — if they do they will have no reward when they stand before God in heaven.

Giving to the needy (secretly).
v.2-4 Don't announce when you are giving to the needy (it goes without saying that Jesus' disciples will be generous givers). Applause from men will be all the reward you will get. Jesus calls those who announce their giving hypocrites. A hypocrite claims to have a good relationship with God but is self-seeking and self-deceived (rsb). One form of hypocrisy is doing the right things but for the wrong reasons. The Pharisees loved the praise from man more than the praise from God (Jn 12:42-43). The way given here to avoid hypocrisy is to give in secret. Don't let your left hand know what your right hand is doing (i.e., don't dwell on it in your own thoughts) Your Father in heaven sees in secret and will reward you..

Read Matthew 6:1-4