God wants guidance for humankind, and to show the right path He sent books and revelations.  For example, He sent the "Suhof" to Abraham, the Torah to Moses, the Psalms to David and the Gospel to Jesus, the son of Mary; and finally, He sent the Quran to Prophet Muhammad, may the mercy and blessings of God be upon them all.  Prophet Muhammad, may the mercy and blessings of God be upon him, is the last of God’s Prophet sent to all people till the end of the world.  Prophet Muhammad said, "Every Prophet was sent to his nation exclusively, but I was sent to all humankind."[1]

The Quran is God’s word and no other book in this world is as important to read.  "This (the Quran) is nothing but evidence from your Lord, and a guidance and a mercy for a people who believe." (Quran 7:203).  The Quran mentions that humankind will be shown "signs" that lead to Him.  In fact, the translated word "signs" is of such great importance in the Quran that it is mentioned over 150 times, and in every instant it is referring to God’s signs.  God equipped humankind with intellect so that we may reflect, analyze, conclude, and then act on His signs.  In addition to our given intellect, every human being is born with a pure and natural inclination that God is our Lord and that He is One.

The following are some of the types of signs mentioned in the Quran:

1)The human conscience

God says that He will show us clear signs in ourselves and that He will come in between us and our hearts.

"We (God) will show them Our signs in the horizons and within themselves until it becomes clear to them that it [Islamic Monotheism] is the truth…" (Quran 41:53)

"O you who have believed, respond to God and to the Messenger [Muhammad] when he calls you to that which gives you life.  And know that God intervenes between a man and his heart and that to Him you will be gathered." (Quran 8:24)

How might God come in between a human and his heart? For example, if one is on the verge of engaging in a harmful act or a major sin there will be an extremely heavy and guilty feeling in that person’s heart.  Such a feeling is actually a warning that doing that sin will anger God. 

2)Certain occurrences

A black cat passing by a house or a magpie landing in one’s garden do not mean anything, and cats and magpies are simply creatures that go about their lives as they wish to; they do not bring good or bad luck.  Superstition is nothing but a deceptive feeling; in reality it does not exist.  However, some events/occurrences do mean something, such as mentioned in the Quran after Cain, the son of Adam, murdered his brother Abel.  "Then God sent a crow digging [a grave] in the ground [for a dead crow], in order to show him how to bury the corpse of his brother.  He (the murderer) said: ‘Woe to me! Have I even failed to be like this crow and bury the corpse of my brother?’ So he became regretful." (Quran 5:31) Cain understood that it was not a coincidence that as the body of his murdered brother lay in front of him a crow appeared and started digging the earth underneath its feet. 

Likewise, when the Pharaoh ignored Prophet Moses’s call to God and refused to release the Israelites, God sent to the Pharaoh and his people signs (in total there were 9 signs).  These signs included locusts that almost totally wiped out all crops in the area, lice, frogs in unprecedented numbers, and continuously bleeding noses; and instead of referring these to God as signs to believe in God and release the Israelites, the Pharaoh got superstitious and said they were done by Moses, the "magician".  "So We (God) sent upon them the flood and locusts and lice and frogs and blood as distinct signs, but they were arrogant and were a criminal people" (Quran 7: 133)

3)Destroyed people and civilizations

At the time of Prophet Muhammad it was well known that there were previous civilizations that God destroyed (after they disbelieved in their sent Prophets) through "mother nature." Such civilizations included the people of Aad, Thamud and Lot.  "And We (God) have already destroyed what surrounds you of [those] cities, and We have diversified the signs that perhaps they might return [from disbelief]." (Quran 46:27). 

The ruins of such civilizations were at the time of Prophet Muhammad still visible and preserved for passersby.  After the destruction of the Pharaoh at the time of Prophet Moses, it was God’s will that entire civilizations (that denied their sent Prophet’s message) would not be destroyed in this life; instead they would be judged in the next life.  Still, one does not have to look far to see signs of retribution such as the destroyed city of Pompeii, a city that was renowned for its open sin and sodomy.  "So We (God) seized each [people] for their sin: against some of them We sent a storm of stones, some were overtaken by a [mighty] blast, some We caused the earth to swallow, and some We drowned. It was not God who wronged them, but they wronged themselves." (Quran 29:40)  

One should be fully aware that earthquakes, volcanos, hurricanes, droughts and other acts of nature are not coincidences, however, acts of God that happen as punishment to people who disbelieve and/or are in overwhelming sin (and do not repent) are also clear signs for people to believe in Him and respond to His call.  "And disasters will continue to afflict the disbelievers or strike close to their homes for their misdeeds, until the promise of God comes to pass.  Indeed, God never fails in His promise." (Quran 13:31) On the contrary, had all humankind believed in God and all His Prophets perhaps there would be no natural disasters, instead more blessings would have come in the form of suitable rainfall, fruits, vegetables and crops.  "And if only the people of the cities had believed and feared God, We (God), would have opened upon them blessings from the heaven and the earth."  (Quran 7:96)

4)Nature

What is present on earth in the form of forests, rivers, mountains, waterfalls, oceans, and diverse plant and animal species is truly something remarkable. It is not the dolphin that equips itself with the most advanced and efficient sonar system on earth, nor is it the eagle that equips itself with eyesight four or five times stronger than that of humans – they both are the works of the Creator Who perfected everything He made. Looking at His creation is one way to know how remarkable and capable the Creator is.

God shows us signs in the animals He created to serve us. Horses, mules, and donkeys are for humankind to ride on to faraway places that otherwise would have taken longer to reach on foot. Cows, sheep, and goats produce milk, and we use their hides and wool for clothing, and we slaughter them for meat; while chickens lay millions of eggs daily – all of these are signs so that we may acknowledge God’s blessings on us and be thankful to Him. "And indeed, for you in grazing livestock is a lesson. We (God) give you drink from what is in their bellies – between digested food and blood – pure milk, pleasant to drink. And from the fruits of the palm trees and grapevines you derive intoxicants and wholesome provision. Indeed in this is a sign for those who understand." (Quran 16:66-67)

Looking up to the sky above us; the earth’s atmosphere was made with a unique protective layer. The sun gives us light that makes life possible, its tilted axis gives us four seasons so that we may enjoy different climates. The stars, comets, and everything that we can see in space are for us to gaze at, admire their beauty, acknowledge that God created the universe, and acknowledge that it surely must have been created for a purpose. In fact, everything in our universe was made for us. "Indeed, in the creation of the heavens and earth, and the alternation of the night and the day, and the ships which sail through the sea with that which benefits people, and what God has sent down from the heavens of rain, giving life thereby to the earth after its lifelessness and dispersing therein every [kind of] moving creature, and [His] directing of the winds and the cloudscontrolled between the heavens and the earth – [in all of this] are surely signs for people of understanding." (Quran 2:164)   

Diversity of humans, opposite genders, and everything good in life are also all signs of God’s ability to do anything and of His kindness. "And of His signs is that He created for you spouses from among yourselves so that you may find tranquility in them; and He placed between you affection and mercy. Indeed in that are signs for a people who give thought. And of His signs is the creation of the heavens and the earth and the diversity of your languages and your colors. Indeed in that are signs for those of knowledge." (Quran 30:21-22)

Not only is rainfall a blessing and water the source of all life, but the frequent mention of rainfall in the Quran is for a much grander purpose. "And it is He who sends the winds as good tidings before His mercy (rain) until, when they have carried heavy rainclouds, We drive them to a dead land and We send down rain therein and bring forth every type of fruit. Similarly, We will bring the dead to life, so perhaps you will be mindful." (Quran 7:57) "And of His signs is that you see the earth barren, but when We send down upon it rain, it quivers and grows. Indeed, He who gives it life is the Giver of Life to the dead. Indeed! He is Able to do all things." (Quran 41:39) After it rains one should remember that God (through the known biological and chemical processes) turns a dead seed into living vegetation. This should make one acknowledge that similar to how God makes a dead seed come to life He will on the Day of Judgment bring back to life and resurrect all of humankind for judgement.  Knowing this should lead one to prepare for that unprecedented Day by doing what pleases God and avoiding what angers Him.

Hence God shows humankind signs that if followed lead to true guidance to Him; a guidance that is brighter than the sun. This guidance is Islam. "And if they submit [in Islam], they are rightly guided; but if they turn away – then upon you is only to deliver [the message]. And God is Seeing of [His] servants." (Quran 3:20) "This day I (God) have perfected for you your religion, completed My favor upon you, and have chosen for you Islam as your religion." (Quran 5:3) As for people who deny God’s signs, the signs will be evidence used against them on the Day of Judgment. Whoever responds to God’s signs and follows His path will be rewarded with the ultimate eternal bliss, Paradise, and whoever denies God’s signs will be punished with the ultimate eternal misery, Hellfire.