Some read this and think we are not to be seen or known for good things we do. I believe that to be a misreading of the text. What it comes down to is the motivation for your 'acts of righteousness'. Matthew tells us not to do them before others in order to be seen by them. In other words, check the motive. Are you doing good so that others can see how good you are, or are you doing good regardless of whether others see you or not? Modeling righteousness can be instructive and inspiring. But if it's motivated by human pride-- hoping for, or expecting accolades, then how righteous is it?
Readings: Genesis 16:1-18:19; Matthew 6:1-24; Psalm 7:1-17; Proverbs 2:1-5