Allah says:
ۗ قُلْ هَلْ يَسْتَوِي الَّذِينَ يَعْلَمُونَ وَالَّذِينَ لَا يَعْلَمُونَ ۗ إِنَّمَا يَتَذَكَّرُ أُولُو الْأَلْبَابِ
Say, “Are those who know equal to those who do not know?” Only they will remember [who are] people of understanding. (Az-Zumar 39:9)
Islam encourages seeking knowledge and spreading it and warns against not seeking knowledge and hiding it if you posses it. The above verse shows that knowing is praiseworthy and being ignorant is blameworthy.
The Prophet Muhamad said:
“من دعا إلى هدى كان له من الأجر مثل أجور من تبعه لا ينقص ذلك من أجورهم شيئاً، ومن دعا إلى ضلالة كان عليه من الإثم مثل آثام من تبعه لا ينقص ذلك من آثامهم شيئاً”.
Whoever invites to good, will get the reward of the doer of good (Sahih Muslim)
People before Islam were in a state of ignorance, they were upon misguidance and Shirk,
يَا أَيُّهَا النَّاسُ اعْبُدُوا رَبَّكُمُ الَّذِي خَلَقَكُمْ وَالَّذِينَ مِن قَبْلِكُمْ لَعَلَّكُمْ تَتَّقُونَ
O mankind, worship your Lord, who created you and those before you, that you may become righteous. (Al-Baqarah:21)
وَمَا خَلَقْتُ الْجِنَّ وَالْإِنسَ إِلَّا لِيَعْبُدُونِ
And I did not create the jinn and mankind except to worship Me. (At-thariyaat:56)
وَمَا أُمِرُوا إِلَّا لِيَعْبُدُوا اللَّهَ مُخْلِصِينَ لَهُ الدِّينَ حُنَفَاءَ وَيُقِيمُوا الصَّلَاةَ وَيُؤْتُوا الزَّكَاةَ ۚ وَذَٰلِكَ دِينُ الْقَيِّمَةِ
And they were not commanded except to worship Allah , [being] sincere to Him in religion, inclining to truth, and to establish prayer and to give zakah. And that is the correct religion (Al-Bayinah:5)
What is worship?
Worship is a comprehensive word that includes everything that Allah loves and is pleased with from speech and deeds, apparent and hidden. It is being dutiful to Allah in all he commanded, Prayer, Zakat, Fasting, Hajj, oaths, supplications is all worship. Allah says:
قُلْ إِنَّ صَلَاتِي وَنُسُكِي وَمَحْيَايَ وَمَمَاتِي لِلَّهِ رَبِّ الْعَالَمِينَ
Say, “Indeed, my prayer, my rites of sacrifice, my living and my dying are for Allah , Lord of the worlds. (Al’an’aam:162)
فَصَلِّ لِرَبِّكَ وَانْحَرْ
So pray to your Lord and sacrifice [to Him alone]. (al-kawthar: 1-2)
وَأَنَّ الْمَسَاجِدَ لِلَّهِ فَلَا تَدْعُوا مَعَ اللَّهِ أَحَدًا
And [He revealed] that the Masjids are for Allah , so do not invoke with Allah anyone. (al-Jinn: 18)
وَمَن يَدْعُ مَعَ اللَّهِ إِلَٰهًا آخَرَ لَا بُرْهَانَ لَهُ بِهِ فَإِنَّمَا حِسَابُهُ عِندَ رَبِّهِ ۚ إِنَّهُ لَا يُفْلِحُ الْكَافِرُونَ
And whoever invokes besides Allah another deity for which he has no proof – then his account is only with his Lord. Indeed, the disbelievers will not succeed. (al-muminoon:117)
The above verses show that prayer and supplication to others is Major Shirk that nullifies and opposes the basic principles and belief of the Muslim.
All the Prophets and Messengers called and instructed their followers to worship Allah and to be sincere and devout worshippers. Allah says:
وَلَقَدْ بَعَثْنَا فِي كُلِّ أُمَّةٍ رَّسُولًا أَنِ اعْبُدُوا اللَّهَ وَاجْتَنِبُوا الطَّاغُوتَ ۖ فَمِنْهُم مَّنْ هَدَى اللَّهُ وَمِنْهُم مَّنْ حَقَّتْ عَلَيْهِ الضَّلَالَةُ ۚ فَسِيرُوا فِي الْأَرْضِ فَانظُرُوا كَيْفَ كَانَ عَاقِبَةُ الْمُكَذِّبِينَ
And We certainly sent into every nation a messenger, [saying], “Worship Allah and avoid Taghut.” (an-Nahl: 36)
The Prophet Muhamad (peace and blessing be upon him) was the final messenger and he was sent to all humanity. He spent 13 years in Makkah calling people to worship Allah, and warning them from Shirk, teaching them and clarifying the meaning of Laa Ilaaha illAllah. Some people responded and accepted Islam in Makkah, while most people rejected arrogantly and was too proud to submit to Islam.
Then the Prophet emigrated to Medinah with his companions the Muhajiroon, and the message of Islam spread between the people of Medinah who embraced Islam, called the Ansaar and the Muhajiroon, who strove hard and fought to establish Islam. They wrote letters to Kings and leaders teaching them about Tawheed and Islam. The Prophet and his companions remained patient and constant in their struggle to convey the message of Islam. Islam became widespread, people became muslims in the hundreds and thousands and Tawheed spread and Shirk was banished from Medinah and Makkah.
هُوَ الَّذِي أَرْسَلَ رَسُولَهُ بِالْهُدَىٰ وَدِينِ الْحَقِّ لِيُظْهِرَهُ عَلَى الدِّينِ كُلِّهِ وَلَوْ كَرِهَ الْمُشْرِكُونَ
It is He who has sent His Messenger with guidance and the religion of truth to manifest it over all religion, although they who associate others with Allah dislike it. (At-Tawbah: 33)
It is a duty on every muslim to be a caller to Tawheed and a warner from Shirk. Like it is a duty on every muslim to ask reliable scholars about things in Islam that are unclear to him or her so that he worships Allah properly and puts into practice:
وَمَا أَرْسَلْنَا قَبْلَكَ إِلَّا رِجَالًا نُّوحِي إِلَيْهِمْ ۖ فَاسْأَلُوا أَهْلَ الذِّكْرِ إِن كُنتُمْ لَا تَعْلَمُونَ
So ask the people of knowledge if you do not know. (al-Anbiyaa: 7)
The Prophet (peace and blessings of Allah be upon him) said:
Whoever takes a path seeking knowledge, Allah will make easy for him the path to paradise
It is known that humanity was not created for no reason, or for a silly goal and purpose, but for a wisdom and for a lofty noble purpose which is to worship Allah alone. Allah says:
وَمَا خَلَقْتُ الْجِنَّ وَالْإِنسَ إِلَّا لِيَعْبُدُونِ
And I did not create the jinn and mankind except to worship Me. (at-thariyaat: 56)
It is not possible to know how to worship Allah, except by studying and reading the Quran, the revelation from Allah to humanity, and the Sunnah of the Prophet, the application of the Quran.
This is the only way to know what is right from wrong, and to work towards being a faithful believer of Allah to attain success in this life and salvation in the afterlife.