Should I boycott my friend for leaving the congregational prayer?

The question: His second question says: I have a colleague who lives with me, and I know that he prays, but not in the mosque. He is more knowledgeable than I am in matters of religion, and I pray in the mosque. Is there anything required of me regarding this, or does any sin attach to me for remaining with him?
The answer: You must advise him for the sake of Allah, and teach him that prayer in congregation is obligatory, and that it is among the most important of the obligations of prayer. It is authentically reported from the Prophet (peace and blessings be upon him) that he said: , . So this blind man was not granted a dispensation by the Prophet (peace and blessings be upon him) to pray in his house, even though he was blind and had no guide to lead him. In one narration, it is mentioned that his house was far away—distant from the mosque—and yet the Prophet (peace and blessings be upon him) ordered him to pray in congregation.
Therefore, it is obligatory for all Muslims, the men, to pray in congregation, to pray in the mosques, as the Prophet (peace and blessings be upon him) and his Companions did; they used to pray in the mosque, may Allah be pleased with them. He commanded prayer in the mosques and informed that whoever hears the call to prayer and does not come, he has no prayer, except for one who has an excuse, such as illness or the like. So you must advise this man, warn him of Allah (Mighty and Majestic), and say to him: "My brother! Fear Allah, pray in congregation, and do not leave the congregational prayer." If he persists in leaving the congregation and does not pray with the people, then he deserves to be boycotted; he deserves that you boycott him and leave his company, lest he enmity you and you delay from the congregation. For sins are like leprosy; their owners may spread it, they spread it to people, and they may cause the disease to transfer to others. So the one who displays sin and advice does not benefit him deserves to be boycotted, and he should not be taken as a companion or a friend, and his invitation to a wedding feast or the like should not be accepted, until he realizes the ugliness of what he has done, and that he is worthy of being boycotted by his upright brothers if he displays sin and does not care about people. Like the one who displays leaving prayer in congregation in the mosques, or displays drinking intoxicants, or displays shaving the beard and does not care and does not accept advice, or displays undutifulness to his parents and not being dutiful to them, or displays letting garments hang below the ankles and dragging them and does not accept advice, or displays smoking openly. Smoking is one of the ugliest diseases and it is a great evil. So it is obligatory for the one who uses it to repent to Allah from it. Just as intoxication is forbidden, a wrong, and a major sin, so smoking contains in it great evil and a great affliction. It is obligatory to leave these sins and beware of them. There is no objection, rather it is prescribed to boycott their people if they do not reform and do not leave what they are upon, except if the boycott may increase the evil, and may lead them to evil, then it should be left, and it should be replaced with constant advice and constant guidance for these people until Allah guides them and those like them.