Wudhu is a Cleanser
Rasul Allah (sal Allahu alaihi wa sallam) said, “When a servant makes wudhu and washes his mouth, the sins committed by his mouth are washed out. When he cleans his nose, the sins are cleansed from his nose. When he washes his face, the sins of his face are washed off, even from under the eyelids. When he washes his hands, the sins of his hands are washed off, even from beneath the nails of his hands. When he wipes his head, the sins from his head come off, even from his ears. When he washes his feet, the sins of his feet are washed off, even from under his toe nails. Then his walking to the Masjid and prayers are rewarded separately.” [Nasaai]
From this hadith we learn that not only is wudhu a physical cleanser of the dust and grime that accumulates on our bodies, but that it is a spiritual cleanser as well. Allah Mighty and Majestic, in His Infinite Mercy, has granted us purification from our minor sins with the performance of wudhu. Sins committed by a particular part of the body are washed off by the water that flows over it. So for example, the sin of having seen something indecent will be removed by the washing of the face. As no body that is washed five times a day can be dirty, so also no soul that is washed five times a day can be filthy.
This purification is of minor sins, major sins (enormities) need conscious repentance to be made of them.