In Islam cleanliness is meant to be half of faith. It has its importance in Islamic as well as scientific view. Who does not stay clean gets sick more often.
Our Holy Prophet Muhammad (Peace be upon him) said to keep ourselves clean from the inside which means our souls and outside which means our bodies. Staying clean from the inside means keeping our thoughts and intensions clean for everyone. By doing this, we will be able to stay away from evil.
If we keep ourselves clean we will stay health and active. Maintaining cleanliness has many other benefits so we should keep ourselves clean.