Answer to the "Do believers always have to be together, or can they live by the religion on their own?" deceit

Every believer who is true in his faith must live according to the Qur'anic morality. In the Qur'an we are frequently reminded that believers always have to be together in order to support and help one another:

Hold fast to the rope of Allah all together, and do not separate. Remember Allah's blessing to you when you were enemies, and He joined your hearts together, so that you became brothers by His blessing. You were on the very brink of a pit of the Fire, and He rescued you from it. In this way Allah makes His Signs clear to you, so that hopefully you will be guided. (Surah Al 'Imran, 103)

Allah loves those who fight in His Way in ranks like well-built walls. (Surat as-Saff, 4)

Restrain yourself patiently with those who call upon their Lord morning and evening, desiring His face. Do not turn your eyes from them, desiring the attractions of this world. (Surat al-Kahf, 28)

Allah's Messenger (pbuh) mentions the same subject by saying that believers are each other's guardians: "Each of you is a guardian, and each of you will be asked about your guardianship." (Bukhari, Muslim)
Clearly, the expression "do not turn your eyes from them" stresses that, apart from being together, believers have to be very attentive to one another and be available to serve other believers so that an Islamic society can be maintained. Another verse describes our Prophet's (pbuh) concern for believers, which is truly exemplary, in the following words:

A Messenger has come to you from among yourselves. Your suffering is distressing to him. He is deeply concerned for you, and is gentle and merciful to the believers. (Surat at-Tawba, 128)

As these verses make clear, "being alone" and "living by the religious morality" are incompatible concepts, and Islam does not support such a model of living. Someone who claims to be able to live by the religion on his or her own has a flawed understanding. As we said earlier, believers are responsible for enjoining good and forbidding evil and for summoning people to the truth. Believers must be together in order to obey this and other commands.
This aside, Islam is founded on the basis of love, for Allah inspires love in believers' hearts for other believers. A believer's love is first for Allah and then for the people who abide by the Qur'an's values. It is unthinkable that people who share such a love based upon Allah's consent, who strive to display the same moral perfection and intend to live together for all eternity, can remain apart and involve themselves in different affairs. Such a mindset is a clear manifestation of the absence of genuine love and faith. The fact is, however, as the verse maintains, that "the believers are brothers…" (Surat al-Hujurat, 10), and brothers do not remain apart.
Our Prophet (pbuh) has stated that believers must always be together and must be attached to each other with a strong friendship and love:

Narrated by Abu Musa: The Prophet (pbuh) said, "A believer to another believer is like a building whose different parts enforce each other." The Prophet (pbuh) then clasped his hands with the fingers interlaced. (Sahih Bukhari, Volume 2, p. 569)
Numan Bin Bashir narrated that the Prophet (pbuh) has said, "The believers in their mutual kindness, compassion and sympathy are just like one body. When one of the limbs is afflicted, the whole body responds to it with sleeplessness and fever". (Sahih Bukhari, Volume 13, p. 6005)