Praise be to Allah, The Lord (The One and Only) of the worlds, and blessings and peace be upon our Master Muhammad, the Truthful and the Faithful.

Dear noble brothers,

One of the reasons behind nations' destruction:

﴾They used not to forbid one another from the Munkar (wrong, evil-doing, sins, polytheism, disbelief, etc.) which they committed.﴿ 

[Al Ma'idah, 79]

"Courtesy" reflects the reality of most Muslims nowadays, for they are courteous with the powerful and the rich no matter how many sins they commit.

Furthermore, though the powerful or the rich might trespass the limits, everyone praises, respects and glorifies him. 

(Verily, Allah the Almighty gets angry when a dissolute is praised.)

If a relative visits the head of the family, and he is known for being religiously uncommitted, for his deviated ideology and for his corrupted beliefs, yet the father says to his children, "Glory be to Allah, how smart and clever this person is", what harm has the father done to his children? He has confused them greatly (due to contradicting himself). 

(Verily, Allah the Almighty gets angry when a dissolute is praised.)

Accordingly, you should choose your words carefully, because praising someone means approving his acts.

Praise be to Allah, The Lord (The One and Only) of the Worlds, and blessings and peace be upon our Master Muhammad, the Truthful and the Faithful.