The Gospel reading is part of the collection of teachings of Jesus put together by St. Matthew in the Sermon on the Mount. Jesus tells us that we are to perform our acts of charity, our acts of penance such as fasting and our prayer not for show before people, but done in secret so that no one knows but our heavenly Father who will then reward us.
We should not do acts of charity in public so that others will praise us nor pray in the sight of all so that all may see us nor parade our fasting and acts of penance so others may know we are doing penance. If we do so, we would “have already been paid in full.” What is much more important is that we are rewarded not by the praise and recognition of people but we are rewarded by our heavenly Father.
It is very significant to note how many times in the Gospel reading Jesus mentions our heavenly Father, “your Father,” “who sees what is kept secret [and who] will reward you.” We pray for this familiarity with and abiding confidence and trust in our heavenly Father