The true God is the Creator and worshiping other than the true God implies the claim that they are deities. The God must be a creator and the proof of his being a creator must be either by witnessing what he has created in the universe or by revelation from ...
The testimony of faith, which includes testifying the Creator's oneness and worshiping Him alone along with testifying that Muhammad is His slave and messenger.
As for the angels, they are great creatures of Allah. They were created from light and have a natural disposition to goodness. They obey the commands of Allah Almighty, exalt Him, and worship Him without ever getting bored or tired.
