Islam is a religion of cleanliness.
Allah says: O children of Adam, take your adornment upon attending every Masjid, and eat and drink, but do not waste. Indeed, He does not love the wasteful. (7:31)
It is a religion of purity. Allah says: Indeed, Allah loves those who are constantly repentant and loves those who purify themselves. (2:222)
Purity is a condition for prayer to be regarded as valid, and prayer is an act of worship which a Muslim performs at least five times throughout his daily routine. Islam also requires that one wash fully after ejaculation or sexual intercourse, and highly encourages washing fully before performing those types of worship which are manifest symbols of Islam, such as the Friday Prayer and the Greater and Lesser Pilgrimage to Makkah.
Allah says in the Glorious Qur’an:
O you who have believed, when you rise to [perform] prayer, wash your faces and your forearms to the elbows and wipe over your heads and wash your feet to the ankles. And if you are in a state of sexual impurity, then purify yourselves. But if you are ill or on a journey or one of you comes from the place of relieving himself or you have contacted women and do not find water, then seek clean earth and wipe over your faces and hands with it. Allah does not intend to make difficulty for you, but He intends to purify you and complete His favor upon you that you may be grateful. (5:6)
It is also encouraged that one keep his mouth and teeth clean. The Messenger of Allah said: “Had I not found it difficult for my followers, I would have ordered them to brush their teeth before every prayer.” (Bukhari)
It encourages that one cleanse and purify those places that may become a breeding ground for germs and filth. The Messenger of Allah, Muhammad said: “There are five acts which are from the innate nature with which Allah created humans: circumcision, removing the pubic hair, plucking the hair of the armpits, shortening the moustache, and clipping the nails.” (Bukhari)