There are many good points of thinking and talking good about others. Among them are:
(i) if you spread and spray good perfume, then the others will do to you too. Therefore all of us will smell good all day long
(ii) if you speak well of others, for example, he and them always pray at the mosque 5 times a day then their action will pull you doing the same good deeds today and many more days to come. Insyallah. . Thus u get more berkat in the friendship
(iii) if you promote positively of your friend by saying he is istiqamah in reading Quraan ( 15 minutes daily before sun sets) then Allah will put in your heart the love of reading Quraan, obeying his commandments and then one day ..the others will look at you like the walking Quraan. Remember: the sahabah r.a. aj main.
(iv) if you say your friend is a charitable person (murah memberi sedekah) then Allah opens your heart to donate freely in what ever circumstances you are in and
(v) finally , two friends who have not seen each other for so long ... say 30 years when he is from Leeds and you from Kota Bharu Kelantan , suddenly both of you meet and shake hands and embrace each other out of the sheer happiness, in markaz dakwah Sri Petaling , Kuala Lumpur, before you depart , Allah will forgive all your sins.
See that is the beauty of friendship in Islam. I always pray so that my chinese , indian teachers (where ever you are ).. Allah will give them islam and hidayah. Ameen. Why? they are always my teachers who taught me very well - mathematics, physics, biology, chemistry, english literature, civics, .. , and many more. TQ teachers.
Please I can't stand looking you in trouble my dear teachers .. one day in the day of reckoning.
Therefore speak well of others will you?