A fundamental benefit of marriage is to be safe from the devil and to safeguard the private parts. The Prophet (Sallallahu Alayhi Wa Sallam) said: "If a man marries, half of his religion is saved. Fear Allah for the remaining half."
The Prophet (Sallallahu Alayhi Wa Sallam) said: "let one who is unable to marry fast, as fast for him is the means of controlling passion."
There is no benefit in a thing of which there is no pleasure. Allah created pleasure of the world with the object that if people have pleasure they will be eager to have lasting pleasure of the next world. To get this pleasure divine service is necessary.
Marriage is a means of saving oneself from the oppression of sexual passion. The Heart is the root of all actions of a traveller towards the next world. Ibn Abbas RA said: "The worship of a man does not become perfect without divine service. Man has been created weak." Akramah and Mujahid explain that man cannot be patient regarding women.
Allah says: "When there falls the darkness of night, seek refuge from its evils." The Prophet (Sallallahu Alayhi Wa Sallam) said: "0 Allah! I seek refuge to Thee from the evils of my ears, my heart and myself." He said: "I pray to Thee for purity of my mind and protection of my private parts."
The Prophet (Sallallahu Alayhi Wa Sallam) said: "If the look of man falls on my woman, let him turn it towards himself and cohabit with his wife, in that case his evil desire will go away."
Jaber RA reported that once the Prophet (Sallallahu Alayhi Wa Sallam) looked to a certain woman. He soon went to his wife Zainab RA and performed his necessity. After that he came out and said: "If a woman comes in front, she comes as a devil. If one of you sees a woman who pleases him, let him come to his wife as what is near that woman is also near his wife."
The Prophet (Sallallahu Alayhi Wa Sallam) said: "Do not go to a woman in absence of her husband as the devil runs through your veins like the circulation of blood." We asked him: "In your case also, O Rasoolullah? He said: "In my case also but Allah helped me over him and he submitted to me." This means: "I have been saved from the machinations of the devil."
~ Ghazali, Ihya ~