The Prophet (sal Allahu alaihi wa sallam) said: “Any person who cherishes in his heart sentiments of love and sincerity for his brother, should express his sentiments to his brother and tell him clearly that he holds him in love and affection.” [Abu Dawud]
If you love someone you should express your love to that person. Its psychological effect on that person is that he will develop a sense of nearness to you. Love will then not merely be a feeling confined to your heart but will begin to play a potent role within practical life.
In the conduct of mutual relationships adopt a moderate course that may be enduring and long lasting. Umar (radi Allahu anhu) observed: “Your love should not assume the form of madness, nor should enmity excite you to perpetrate torture on another.” When asked how we exhibit these extremes in behaviour he stated: “In this manner that if you love someone you start hugging him in a childlike fashion and display other forms of childish behaviour. And if you feel angry with someone, you resolve upon the destruction of his life and property and utter ruination. [Al-Adab-ul-Mufrad]