(هُوَ الَّذِي أَرْسَلَ رَسُولَهُ بِالْهُدَىٰ) (It is He who has sent His Messenger with guidance): Allah (swt) has sent His messenger, Muhammad, (saws), with guidance; that is, the Quran:
إنَّ هَٰذَا الْقُرْآنَ يَهْدِي لِلَّتِي هِيَ أَقْوَمُ
(Indeed, this Qur’an guides to that which is most right) (Al-Israa: 9)
So, the book revealed to the Messenger of Allah, (saws), is the guidance.
(وَدِينِ الْحَقِّ) (and the religion of truth): The true religion is the one that descends from Allah, the Almighty. As for the religions that people have adopted, such as the worship of idols and statues, the worship of the sun and the moon, they are false.
(لِيُظْهِرَهُ عَلَى الدِّينِ كُلِّهِ وَلَوْ كَرِهَ الْمُشْرِكُونَ) (to manifest it over all religion): Someone might say: Muslims are currently lagging behind in civilization, so how this situation cope with Allah’s saying: “to manifest it over all religion“? The answer is that the manifestation here refers to the clarity and conviction of the message, not necessarily to military or economic power.
To illustrate: In America and Europe, there had been significant callings to stop breastfeeding and encourage the use of synthetic milk as a new potential alternative, believing it to be better for infants. After some time, they went back to Islam’s guidance, after discovering that breastfeeding was the best thing for infants. Likewise, the prohibition of alcohol in Islam. They have now discovered the harm of alcohol, leading them to prohibit it in their countries. They don’t prohibit it based on legislation, but for health reasons and societal well-being. Therefore, the manifestation mentioned in the Quran is the prevalence of a convincing argument and conviction. There is no contradiction between the verses of the Quran and true knowledge because the Creator is Allah (swt) and true knowledge does not contradict the Wisdom of Allah (swt). Everything mentioned in the Quran, even if people haven’t discovered it yet, will become evident to them at some time. These include many aspects even to matters related to divorce and marriage. As time passes, it becomes increasingly clear that Islam’s teachings are the correct teachings and Islam’s values are the most-sounded values. This is the manifestation of a convincing argument and conviction.