Divine infinity is not in the mathematical and numerical sense; rather it means absoluteness and possession of all attributes of perfection. The reason man's intelligence is unable to know the essence of God is that things are known through their opposites "By their opposites are all things known." If a thing does not have an opposite, mankind would not be able to know its essence even though that thing might be very unconcealed and tangible.

On the other hand, the term "unlimited" refers to an existent which is unbounded and without end. In fact, endlessness means that the existent is absolute. The term "absolute" has different applications one of which is 'absolute versus restricted'. When an existent is qualified as absolute, we remove all kinds of restrictions and limits from it and call it as unlimited.

It is not possible for us to know the essence of God, the Exalted, but our intellect can perceive that, first, every existing phenomenon in the world is in need of a cause. As per the 'principle of the impossibility of circle and endless chain [of causes]', these existents should end up in a being that is the ultimate being and the cause of all causes. Thus, the ultimate cause should be at the highest level of existence so as to be the cause of all beings other than its own being. When we say that God, the Exalted, is without end and unlimited, it means that He is at the highest level of existence.

Therefore, in the first place, our knowledge is about God as an entity that is at the highest level of existence. Secondly, we know that such a being that features all attributes and traits of perfection is devoid of any restriction and that anything that limits its existence is opposed to it. The Holy Quran makes a clear reference to this point and says that God has all the attributes of perfection:

لَهُ الْأَسْماءُ الْحُسْنى * وَ لَهُ الْمَثَلُ الْأَعْلى‏ فِی السَّماواتِ وَ الْأَرْضِ وَهُوَ الْعَزِیزُ الْحَکِیمُ.

To Him belong the Most Beautiful Names.[1] To Him belongs the loftiest similitude (we can think of) in the heavens and the earth: for He is Exalted in Might, full of wisdom.[2] 

Therefore, God, is the Alive, the Almighty, the All-Knowledgeable, al-Murid (i.e. He has His own will and discretion in all affairs). He is the Guide, the Creator and the Wise, the Merciful and the Just. Finally, there is no attribute of perfection that He might lack. All these attributes of perfection mean that God, the Exalted, is absolute.

Having said that, we come to the conclusion that  knowing the One God, as the most perfect being with the most perfect attributes and devoid of any imperfection and deficiency and understanding His relationship with the world which is replete with creation, gracefulness and compassion, create a reaction in us which is termed as "worship". Worship and adoration is a kind of submissive, glorifying and thanks-giving relationship between man and his Creator. Man can establish this kind of relationship with God alone and it is true with Him only.[3]

On the other hand, man is born with a God-seeking nature. His prosperity, perfection, salvation and good, rest in cognition of God, worshipping of him and getting proximity to Him.[4] The journey towards God and achieving perfection are actualized with different levels of understanding and cognition of Him. However, it should be noted that not knowing the essence or the very exact nature of God is not in any way opposed to divinity and to God's being worthy of worship and adoration.