Allah Almighty says: {On that Day close friends will be enemies to one another, except for the pious.} [ِِِAl-Zukhruf: 67]
1) Anything that is done for the sake of Allah lasts, and anything that is done for other than Him is doomed to perish. So, those who befriend in life for mundane interests will turn into enemies in the Hereafter.
2) This gives glad tidings for those who are bonded by sincere friendship. So, a believer should be keen to be one of them.
678/1 - Abu Sa‘īd and Abu Hurayrah (may Allah be pleased with both of them) reported that the Prophet (may Allah’s peace and blessings be upon him) said: “Allah never sent any prophet nor did He assign anyone with authority except that he had two entourages: one entourage enjoins him to do good and encourages him to carry it out; and another entourage enjoins him to do evil and incites him to carry it out; and the protected is the one whom Allah protects.” [Narrated by Al-Bukhāri]
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1) A person is either a caller to Allah Almighty, commanding and encouraging the right and forbidding and warning of the wrong, or a caller to the devil and his allies. Let a wise person see which way to choose!
2) Whoever seeks light from knowledge and faith and applies the Shariah of Allah, Allah will guide him, out of His grace, and protect him from his own evil and from the plots of Satan and his allies.
In relation to the circumstances surrounding this Hadīth, it is reported that the Prophet (may Allah’s peace and blessings be upon him) and Abu Bakr and ‘Umar (may Allah be pleased with both of them) visited Abu al-Haytham al-Tīhān al-Ansāri and ate and drank in his house. When they finished, the Prophet (may Allah’s peace and blessings be upon him) asked him: “Do you have a servant?” He replied: “No.” The Prophet said: “If we get captives of war, come to us.” Only two captives were subsequently brought to the Prophet (may Allah’s peace and blessings be upon him), and Abu al-Haytham went to him. The Prophet (may Allah’s peace and blessings be upon him) said: “Choose one of them.” He said: “O Messenger of Allah, choose for me.” Thereupon, the Prophet (may Allah’s peace and blessings be upon him) said: “Indeed, a person consulted is a person given a trust. Take this one, for I have seen him pray, and treat him kindly.” His wife said: “You will not be able to fulfill the Prophet's instruction regarding him except by setting him free.” He said: “He is free.” Thereupon, the Prophet (may Allah’s peace and blessings be upon him) said: “Allah never sent any prophet nor did He assign anyone with authority except that he has two entourages...”
So, the Hadīth literally pertains to the entourages of prophets and caliphs, yet it was said in connection to family affairs. This is because when the family is good, society becomes good, and so does the entire Ummah. So, a man should carefully choose a righteous wife, who will be a good entourage that encourages him to do what is right and discourages him from doing what is wrong. And Allah knows best.
679/2 - ‘Ā’ishah (may Allah be pleased with her) reported that the Prophet (may Allah’s peace and blessings be upon him) said: “If Allah wills to do good to a ruler, He appoints for him a truthful adviser, who will remind him if he forgets and help him if he remembers. And if Allah wills otherwise for him, He appoints for him a bad adviser who will not remind him if he forgets, nor will he help him if he remembers.” [Narrated by Abu Dāwūd with a sound Isnād that meets the conditions of Muslim]
1) The Shariah prescribes taking a sincere adviser; which is a sign that Allah wills good for him.
2) Rulers are warned against evil retinues, for they are a cause of corruption and transgression.
3) A ruler is exhorted to bring good and righteous people near him and keep evil and treacherous ones away. He cannot have a good retinue unless he brings them near.