The Declaration of Faith
The Declaration of Faith, known as the Shahada, is a necessary and significant step every Muslim must take as soon as possible. As the name suggests, it is a simple declaration of belief. It can be said publicly or privately, but it must be said with sincere belief.
For English speakers, it is helpful to say it first in English and then in Arabic, sentence by sentence.
This is the declaration of faith as recited in Shia Islam:
Ashāhadu an lā ilāha illallāh, wa ashhadu anna Muhammadan rasūlullāh, wa ashhadu anna ʿAliyyan waliyyullāh.
We will go through it one sentence at a time: first the Arabic, then the translation.
Ashhadu an lā ilāha illallāh.
I bear witness that there is no god but Allah.
Wa ashhadu anna Muhammadan rasūlullāh.
And I bear witness that Muhammad is the Messenger of Allah.
Wa ashhadu anna ʿAliyyan waliyyullāh.
And I bear witness that Ali is the friend and guardian appointed by Allah.
Once a person sincerely declares this belief, they have entered Islam.