The good Son returns home is a popular saying used to express the act of get back to doing something that he was already used to doing, or visiting and being in an already usual place.
One of the main doubts about this phrase is the use of the back letter in the letter "a". According to modern Portuguese, the crase is used when an identical preposition and article merge ("a" + "a"). However, in "the good son the house makes" there is no backstroke, because there is no article before the word "house", being the letter "a" a preposition that reacts with the verb "makes" ("makes somewhere", for example).
The word "house", when it has the meaning of "place where one lives", "own dwelling", dispenses with the use of an article. Therefore, as there is no article to "merge" with the preposition "a", the back-quote is not used.
In the religious sphere, this expression is related to the famous parable of the "Prodigal son", described in the Christian Holy Bible, in the book of Luke 15: 11-32.
Learn more about the meaning of Parable.
The parable tells the story of two sons who likewise receive their anticipated inheritances from their father. One of the children, however, decides to take all the money he received and leave the house, abandoning the family to enjoy the world's luxuries. A while later, after spending all the savings he had on trifles, he found himself alone and helpless, recognizing the true value of the family and repenting for leaving the father in exchange for mediocrities. Upon returning home repentant, the father receives him with great joy, being happy to see that "the good son returns home".
For Christians, this story represents the beginning of repentance. In other words, even people considered sinners and distorted from the so-called "way of God", if they repent, they will be welcomed with open arms by the Savior. It also means the representation of a kind and merciful God, who does not hold grudges and knows how to forgive and love all his children, including the most "rebellious".