Who should not be befriended according to the philosophy of Islam?

When choosing our friends we should ask ourselves first: Are they
going to help us achieve the purpose for which we were brought to
life? Or will they take us away from it? Will they desire for us
Allah's (SWT) pleasure or is that completely irrelevant to them and
not their concern at all? Are they leading us to Paradise or to the
Hell?
Imam Muhammad al-Baqir (as) narrates from his father who said,"O my
son don't befriend five types of people:
1. Don't befriend a liar (Kadhib). For a liar is like a mirage. He
shows the distant as near and the near as distant. He will always
deceive you and trouble you.
2. Don't befriend a transgressor (Ghasib). Forhe will forsake you for
a paltry sum and make your sins appear very alluring to you. He will
make you a victim of Allah's chastisement through his petty sins and
take you farther away from His obedienceand satisfaction. He will make
Allah's worship appear as His disobedience, and His disobedience as
His worship. He will drag youalong with himself in the fire of hell.
3. Never befriend a miser (Bakheel/Kanjus). For in your time of need
and distress, he will withhold his wealth from you, while he is in a
position to assist you. (He values his wealth more than anything else.
And to thatend he is prepared to forsake even his friends)
4. Do not befriend a fool (Ahmaq). For (in his foolishness) he will
harm you while he intends to help you. (That is why it is said, 'A
shrewd enemy is better than a foolish friend')
5. Don't befriend the one who breaks relations (with his
relatives/Khata Rahmi). For, such a person has been cursed in the
Noble Qur'an in three places. He is engrossed in his own affairs with
scant regard for others. (Friendship with such a person will
eventually lead the individual towards sins and disobedience of
Allah)"
Imam Ali ibn Abi Talib (as) said: "Do not befriend a sinner
(Fasiq/Fajir) because he will sell you for a morsel."
Imam Sajjad (as) said:"Do not make anyone your enemy even though you
consider him harmless and do not turn down a person's friendship even
if you think he will not benefit you."
The Noble Qur'an says,"The hypocritical men and the hypocritical women
are all alike; they enjoin evil and forbid good and withhold their
hands; they have forsaken Allah, so He has forsaken them; surely
thehypocrites are the transgressors." (Surah Al-Tawba, 9:67)
On the other hand, Noble Qur'an discusses the believers in the
followingmanner, "And (as for) thebelieving men and the believing
women, they are guardians of each other; they enjoin good and forbid
evil and keep up prayer and pay the poor-rate, and obey Allahand His
Messenger; (as for) these, Allah will showmercy to them; surely Allah
is Mighty, Wise." (Surah Al-Tawba, 9:71)
The two Qur'anic verses mentioned above only goto show how critical a
role friendship can play in our lives. A true friend then, is the one
who takes us closer to Allah's (SWT) compassion and grace.
Having deliberated at length on who should not be befriended, we shall
now see what kind of people should be befriended. Imam Jafar Sadiq
(as) narrates,"Friendship entails certain trusts and duties. Then the
one who observes these obligations is a true friend and the one who
breaches this trust is unworthy of friendship. These obligations are
as follows;
1. He should be the same outside as he is inside. In other words, he
should not have a dual personality. (In this age however, we often
come across people who are exceptionally humble and modest on the
outside, with little, if any humility, on the inside)
2. He will consider your virtues as his virtues and your misdeeds as
his misdeeds. (In other words your virtues will cheer him and your
faultswill grieve him. God forbid, he must not feel relieved after
observing some vice in you, and take solace from the fact that he
himself is above that vice.)
3. If he acquires a position of power and authority, it must not bring
about a drastic change in his attitude. In other words, prosperity
must not transform the individual adversely. (There are some people
who make the best of friends in adversity. But apositive change in
their financial condition reveals a dark, hitherto unknown side of
their personality. On the other hand we see some people who make good
friends in prosperity, but misfortune transforms them, disclosing
their fickleness.)
4. He must give his friendship (with you) priority over all his
worldly possessions. In other words in times of adversity, he must be
willing to give his all to redeem you.
5. He must never leave you alone in times of misfortune and distress."