Q. Jesus says in the Sermon on the Mount, “When you give to the needy, do not let your left hand know what your right hand is doing, so that your giving may be in secret. Then your Father, who sees what is done in secret, will reward you.” But just a little earlier, Jesus says, “Let your light shine before others, that they may see your good deeds and glorify your Father in heaven.” Which is it? Are we supposed to do our good deeds secretly, so that only God can see, or publicly, so that others will see and praise God?
In these two teachings Jesus is actually addressing two different problems.
The problem he addresses first is people who have a sincere faith but who aren’t living it out through generosity and service to others. They are like “salt that has lost its saltiness” and a “lamp hidden under a bowl.” In other words, they’re supposed to be having a preserving influence on their community and setting the right example, but they’re not. So Jesus tells them to live out their faith through “good works” (not religious performance, but kindness and generosity), and this will lead others to recognize God’s compassionate character and praise Him for it.
The problem Jesus addresses next is people who are doing good works, but with bad motives. They’re giving to the poor just “to be honored by others.” Jesus says that if our sincere desire is to help those in need, we should do so discreetly and quietly, not to be praised by others, but to be part of God’s work of compassion in the world. When we do this, God will be pleased and will bless our efforts. (“Don’t let your left hand know what your right hand is doing” is an example of hyperbole or exaggeration, a technique Jesus often used to make a point. It’s impossible to do literally, but it actually means not calling attention to what you’re doing.)
So we do “good works,” on the one hand, in a way that others can see, not so that we will be praised, but so that God will be glorified for His compassion. But on the other hand we carefully avoid any self-promotion, because it’s not about us being honored, it’s about God’s purposes being advanced and God’s ways becoming known.
There’s a fine line to walk here. A donor might want to make a gift public, and even agree to have their name on a building, for example, to encourage others to give. That would be letting their light shine. But they’d always have to keep a watchful eye on their true motives.