Matthew chapter 6 begins by speaking of two things: the sublime relationship God desires with his creatures and the shameful hypocrisy of religion.
The first thing that catches our attention is the word "Father." It appears 10 times in the first 18 verses of the chapter. Never before had a Jew called God Father. Consider this: in the entire Old Testament, no one would dare to have such intimacy and familiarity with God.
This intimate relationship was inaugurated by Jesus, who in his human form was the only begotten, or the only begotten son of God. He was conceived by the Holy Spirit, born of a virgin, and had Joseph as his legal father, not his biological father.
And what's more: in the New Testament, God is not only called Father. Shortly before his death, when Jesus prayed in agony, the Gospel of Mark says that he addressed God with the word "Abba," which, in Aramaic, means "Daddy." And in the letters of the apostles, you learn that everyone who believes in Jesus can now call God "Daddy."
God extends this relationship of intimacy and kinship to everyone who receives Jesus, and only to them. Listen carefully to what the first chapter of the Gospel of John says:
Jesus "came to his own people, and they did not receive him. But to all who did receive him, to those who believed in his name, he gave the right to become children of God."
Are you a child of God? Have you been born again? Have you believed in Jesus?
Now comes the contrast: Jesus exposes the hypocrisy of the religious man, who gives alms and prays to be seen and praised by men. According to Jesus, this man has already received his reward. What? Well, to be seen and praised by men. What he is saying is that such a man should be satisfied with receiving what he sought. Nothing more.
Almsgiving and prayers are as good as the many fruit trees God planted in the Garden of Eden for Adam and Eve to eat. What happened? They ate from the one tree God commanded them not to eat from. This was the origin of sin, of human rebellion against the Creator.
When Adam and Eve saw the folly they had committed, they tried to hide from God among the trees in the orchard. Religious people are like this: they try to hide from God among the very things God approves, like almsgiving and prayers. They try to disguise, pretend, and cover up their sin. The name for this? Hypocrisy.
Christ Jesus came into the world to save sinners, and these are the ones God seeks. If you continue hiding behind your religion, your good works, and prayers to appear as if you are not a sinner, how do you expect to be found and saved?
Come on, expose yourself, open yourself up, lay yourself bare to God, confess to Him who you really are, and believe in Jesus as your Lord and Savior. That's all it takes for you to be called a child of God and be able to look to God and say, "Daddy."