Tawheed

Towheed: (Shahadah), Declaration of the faith.

LA ILAH ILLALLAH: This means to believe in Oneness of Allah (swt) and not associate any relation or partnership to Him accept the relation betwen God and the servants.
This pillar is the first and the most important part of believing in Islam, without this declaration one can never enter to Islam.

"Say: He is God, the One and Only; God, the Eternal, Absolute; He begets not, nor is He begotten; And there is none like unto Him" . ( Quran chapter 112)

“God is He, than Whom there is no other god;- Who knows (all things) both secret and open; He, Most Gracious, Most Merciful. God is He, than Whom there is no other god;- the Sovereign, the Holy One, the Source of Peace (and Perfection), the Guardian of Faith, the Preserver of Safety, the Exalted in Might, the Irresistible, the Supreme: Glory to God! (High is He) above the partners they attribute to Him.

He is God, the Creator, the Evolver, the Bestower of Forms (or Colors). To Him belong the Most Beautiful Names: whatever is in the heavens and on earth, doth declare His Praises and Glory: and He is the Exalted in Might, the Wise”.
( Quran chapter 59: verses 22-24).

MOHAMMED-UR-RASOOL ULLAH, Every Muslim should believe that, Muhammad (Pbuh) was the messenger of Allah.

These is words are second part of the Shahadah declaration, called Shahadatain and are:

LA ILAH ILLALLAH, MOHAMMED-UR-RASOOL ULLAH.