FRIENDSHIP demands very close correspondence between those who love one
another, otherwise it can never take root or continue. And together
with the interchange of friendship, other things imperceptibly glide
in, and a mutual giving and receiving of emotions and inclinations
takes place; especially when we esteem the object of our love very
highly, because then we so entirely open our heart to him, that his
influence rules us altogether, whether for good or evil. The bees which
make that oriental honey of which I spoke, seek to gather nought save
honey, but with it they suck up the poisonous juices of the aconite on
which they light. So here, my child, we must bear in mind what our
Saviour said about putting out our money to the exchangers;  we
must seek to make a good exchange, not receiving bad money and good
alike, and learning to distinguish that which is valuable from what is
worthless, since scarcely any one is free from some imperfection, nor
is there any reason why we should adopt all our friend’s faults as well
as his friendship. Of course we should love him notwithstanding his
faults, but without loving those faults; true friendship implies an
interchange of what is good, not what is evil. As men who drag the
river Tagus sift the gold from its sands and throw the latter back upon
the shore, so true friends should sift the sand of imperfections and
reject it. S. Gregory Nazianzen tells us how certain persons who loved
and admired S. Basil were led to imitate even his external blemishes,
his slow, abstracted manner of speaking, the cut of his beard, and his
peculiar gait. And so we see husbands and wives, children, friends,
who, by reason of their great affection for one another,
acquire–either accidentally or designedly–many foolish little ways
and tricks peculiar to each. This ought not to be; for every one has
enough imperfections of their own without adding those of anybody else,
and friendship requires no such thing; on the contrary, it rather
constrains us to help one another in getting rid of all sorts of
imperfections. Of course we should bear with our friend’s infirmities,
but we should not encourage them, much less copy them.
Of course I am speaking of imperfections only, for, as to sins, we must
neither imitate or tolerate these in our friends. That is but a sorry
friendship which would see a friend perish, and not try to save him;
would watch him dying of an abscess without daring to handle the knife
of correction which would save him. True and living friendship cannot
thrive amid sin. There is a tradition that the salamander extinguishes
any fire into which it enters, and so sin destroys friendship.
Friendship will banish a casual sin by brotherly correction, but if the
sin be persistent, friendship dies out,–it can only live in a pure
atmosphere. Much less can true friendship ever lead any one into sin;
our friend becomes an enemy if he seeks to do so, and deserves to lose
our friendship, and there is no surer proof of the hollowness of
friendship than its profession between evil-doers. If we love a vicious
person, our friendship will be vicious too; it will be like those to
whom it is given.
Those who draw together for mere temporal profit, have no right to call
their union friendship; it is not for love of one another that they
unite, but for love of gain.
There are two sayings in Holy Scripture on which all Christian
friendship should be built:–that of the Wise Man, “Whoso feareth the
Lord shall direct his friendship aright;”  and that of S. James,
“The friendship of the world is enmity with God.” 
 S. Matt. xxv. 27.
 Ecclus. vi. 17.
 S. James iv. 4.