The prophet's advice

Rules of companionship

1-love for the sake of Allah(to love you friend as long as he obeys Allah,whereas to hate for sake of Allah means to hate him when he turns astray from the way of guidance)

The prophet Mohammad (peace & blessing be upon him) said,"don't rush in loving your friend ,as he may turn (into)your enemy one day.And don't rush in hating your enemy ,as he may turn (into)your friend one day."(narrated by tirmidhi)

قال رسول الله صلى الله عليه وسلم: أحبب حبيبك هونا ما عسى أن يكون بغيضك يوما ما و أبغض بغيضك هونا ما عسى أن يكون حبيبك يوما ما (رواه الترمذي)
The prophet Mohammad (peace & blessing be upon him) said,"whenever any one of you loves a friend for the sake of Allah,he has to let him know this."(narrated by abu dawood)

قال رسول الله صلى الله عليه وسلم: "إذا أحب أحدكم أخاه فليعلمه أنه يحبه"أخرجه أبو داود كتاب الأدب باب الرجل يحب الرجل على خير يراه رقم (5102) "

The prophet Mohammad (peace & blessing be upon him) said,"The best friend is the one who helps you at the time you remember Allah and reminds you at the time you forget Him."(Narrated by Ibn Abud Dunya).

قال رسول الله صلى الله عليه وسلم:خير الأصحاب صاحب إذا ذكرت الله تعالى أعانك، وإذا نسيت ذكرك‏."‏
Again Allah's Messenger (peace & blessing be upon him) said,"the best companion is the one who when you see him you remember Allah,when he talks he adds to your knowledge,and when you see his deeds you remember the Hereafter.")(Narrated by Ibn Abbas).

قال رسول الله صلى الله عليه وسلم:"خير جلسائكم من يذكركم الله رؤيته وزاد في علمكم منطقه وذكركم الآخرة عمله‏."