Piety in relation to monotheism means that man has to know that the All-seeing, the All-hearing, the All-wise, the Maker, the Creator, the Healer and the Provider is the One and Only God and that other beings are His creatures. It is really not very difficult to prove the existence of God. Nevertheless, we would like to mention certain reasons to prove it.
1- Whenever man sees an object in this world, he will automatically think about its producer and inventor. Even if a girl, who has a doll in her hands, is told that this doll has been made by itself, she will laugh at that. How can this universe with the earth, the sky, plants, animals, human beings, waters, mountains, winds, rains, space, planets, light and darkness, fruits, grains and millions of other things exist without a Maker who is All-knowing and All-wise?
2- How can cosmos, the order of days and nights, the four seasons, the function of eyes, ears, heart, digestive tract, and solar system not lead us to the existence of God?
3- In dangers, our hearts are directed towards a Savior and Helper even if we are not Muslims.
4- The news brought by prophets, Imams and the messages of scholars and scientists about an Eternal Being and the Lord of the universe is one of the strongest reasons to prove God’s existence.
When God’s oneness is proved for man, and when man realized that there is no one in this universe save God, who is All-hearing, All-seeing, the King, the Provider of human beings and animals, One who brings forth the living from the dead and brings forth the dead from the living and the Manager of the world, he should exercise this piety that he is not inclined to anything but God.
In this relation, God says: “Say: who gives you sustenance from the heavens and the earth? Or who controls the hearing and the sight? And who brings forth the living from the dead and brings the dead from the living? And who regulates the affairs? Then they will say: Allah. Say then: Will you not then guard (against evil)?”1
That is to say, one should not take heed of false gods or idols, rather he should safeguard himself from vicious circle and deviations which is the same as inclination for idols and their likes.
Regarding this, God has said: “Take not two gods, He is only One God; so of Me alone should you be afraid. And whatever is in the heavens and the earth is His, and to Him should obedience be (rendered) constantly; will you then guard against other than (the punishment of) Allah?”2
That is to say the One who deserves Taqwa is the One God and it is He who punishes, takes us to task and rewards us.
As for those who do not believe, God says: “Surely the vilest of animals in Allah’s sight are those who disbelieve, who will not believe; those with whom you make an agreement, then they break their agreement every time and they do not guard (against punishment).”3