Beliefs are the bedrock upon which the entire religion is built. They are the key to entering Islam and, God willing, Paradise. The Muslim creed, or statement of beliefs, consists of several tenets that are a pre-requisite for the soundness of belief, all of which are implied and contained in the two testimonies:  

Ash-hadu an lā ilāha ill-Āllāh

I testify that nothing is worthy of worship except God,

Wa ash-hadu anna Muḥammad-an rasūl Allāh

And I testify that Muhammad is the messenger of God.

A person formally enters the religion of Islam by uttering these two proclamations, otherwise known as the Testimony of Faith (Shahādah).  

The proclamation starts with absolute negation, “nothing is worthy of worship”— and is followed by the affirming statement, “except God!”. The testimony is a declaration of absolute monotheism—the message of all of God’s prophets. The second half of the Testimony teaches that we must live in accordance with the reality of the first Testimony, and that God taught us how to do so through the life and teachings of His prophets, the last of which was Prophet Muhammad Peace be upon him. 

God informs us in the noble Quran:

I HAVE ONLY CREATED JINN AND HUMANKIND THAT THEY MAY WORSHIP ME

(Quran 51:56). 

This worship entails knowing Him with a knowledge that is substantiated and clear. Beliefs in Islam are therefore rooted in firm knowledge, reason and conviction. The foundations of belief cannot be based upon doubt, or conjecture. 

However, each of these chosen men possessed certain essential characteristics in their special role as Messenger. They are:

• Truthfulness (|Sidq)
• Trustworthiness (amana)
• Intelligence/sagacity (fatana)
• Conveyance (tablÏgh)\