St. John Chrysostom commenting on Christ’s instruction about how his followers are to practice charity, writes:
“‘When you give alms, don’t blow your own trumpet,’ he says, ‘as the hypocrites do in the synagogues and the open streets so as to be praised by people. Truly, I say to you, they already have their reward.’ (Matthew 6:2)
Do you see how the person looking for the former reward loses the latter, whereas the one who practices virtue and aims at avoiding people’s attention will gain recompense from the Lord publicly on that dread day.
‘Your Father,’ the text says, ‘who sees in secret will reward you publicly.’ (Matthew 6:4)
Don’t worry, he says, about the fact that not a single human being commended you, and you practiced virtue unnoticed; instead, set your mind on this fact that the Lord’s generosity will be so great before long, not in a private fashion nor in secret – rather, he will sing your praises and reward you in the presence of the whole human race from Adam till the end of time, and will bestow on you recompense for your works of virtue.” (St. John Chrysostom, Homilies on Genesis 18-45, pg. 239)