The testimony (LA ILAAHA ILLA ALLAH ) comprises two concepts: Denial and Affirmation.
The testimony of faith denies the attribute of divinity to anyoneand anything other than Allah – the Exalted.
All those other than Allah, such as the angels, the Prophets, and the rest of Mankind, let alone the idols and the political regimes in the world, are not gods and thus don’t deserve to be worshipped.
Therefore, denial in this respect is not denial of the existence of the alleged gods, rather the denial of divinity which is attributed to them.
The testimony of faith affirms and restricts divinity to Allah alone. That is, the slave must believe that Allah is the only true God, and accordingly dedicate no act of worship to any, other than Allah.