There is none worthy of worship except Allah (GOD). This means that none truly deserves, or has the right to be worshipped, except Allah (GOD), the Almighty, All-High, since He alone possesses those perfect qualities that are associated with omnipotence, divinity, and godhood.
The spirit and secret of this monotheistic phrase is to single out Allah (GOD) for love, fear, hope, veneration, and glorification. It also includes our depending upon Allah (GOD) and our repenting to Him. So our love is pure for none except Him, and everyone other than Him is only loved as a by, product of our love for Him, or as a means of increasing our love for Him.
Therefore we must fear Allah (GOD) Alone, and we must depend upon Him Alone, in Him Alone do we place our hopes; and of Him Alone are we in awe. We take an oath by His name only, we repent to Him Alone, and all obedience is for Him. In times of hardship, we may invoke none but Him and we may seek refuge in none save in Him. Also, we prostrate to Him only, and when we slaughter an animal, we do it, mentioning His name only.
All of the above can be summarized in one phrase: None has the right to be worshipped except Allah (GOD). This phrase is comprehensive of all forms of worship.