The early leader of what become to be called the Religious Society of Friends, later called the Quakers, was George Fox (1624-1691).
In general, the Quakers adhere to the following.

• The address each other as "friend".
• Avoid oaths and creeds
• Avoid hierarchical structures

Although considered unorthodox by the Anglican Church, the Puritans, etc., these views are supported by what Jesus says in the GNT (Greek New Testament). William Penn of Pennsylvania fame, was a Quaker convert.

As do many modern Christian religions, many Quakers appear to have become more secular (non-Biblical) in their beliefs and practices.