Iman has more than 70 branches. The most excellent among these branches is the saying "Laa ilaaha ill Allah" (there is no god but Allah), and the smallest branch is to remove an obstacle from the wayside. And "Haya" (modesty) is an important branch of Iman.
Narrated by: Abu Hurayrah
Sahih Muslim - Book of Faith (Kitab Al-Iman)