Only Allah is The One True God

Say: He is Allah, (the) One. (112:1)

And for every nation We appointed a ritual (of sacrifice) that they might celebrate the Name of Allah on what He has given them of the four legged cattle; but your God is one God (Allah), then submit to Him, and (O beloved Prophet) give glad-tidings to the humble.

(To) those whose hearts tremble when Allah is mentioned and those who patiently bear whatever befalls them, and those who establish regular prayer and spend (benevolently) out of what We have provided them. (22:34-35)

Say: If there had been (other gods) with Him as they allege, then they would have sought out a way to the Owner of the Throne. (17:42)