Thomas A Kempis 1.8 - Choosing your companions wisely

Avoiding over-familiarity

Not everyone is such that you should you reveal your heart to them. But with someone who is wise and fears God you may pursue your cause. Seldom seek the company of the young and the strangers, nor flatter the rich, nor willingly keep company with the powerful and influential. Associate with the humble and simple, the devout not the worldly, who are focused on constructive things. Do not be familiar with someone of the opposite sex, but commend all alike to God. Only to God and his angels should your wishes be familiar, and avoid the notice of men.

We have love for all, but do not make close companions of all. Sometimes it happens that someone we don't know shines with a good reputation, and then his presence darkens the eyes of the onlookers. We think to please others by displaying our firm convictions, and find that we displease them more as they see the dishonesty of our behavior. 

Imitation of Christ by Thomas A Kempis, 1.8. 

Translation focused on contemporary English and preservation of rhetorical force and art