The Prophet taught Muslims who follow his teachings how to overcome life burdens and social pressure, his teachings safeguard them against psychological diseases which get in the way of human happiness.

Muhammad taught them how to attain happiness and inner peace. The smile was the Prophet’s slogan whether at home or traveling, he was never seen but smiling. 

His sweet smile cured the sadness of all people around him and healed the pains of his companions. 

But he never went over the limits; he did not exaggerate in the way he smiled or laughed, he used to laugh without widely opening his mouth, or cracking, i.e. he was always full of respect.