It's related to the word "valued", which in a higher extent is something that is "great", which is related to the word "exalted" (a higher form of greatness) and God is exalted above all exalted ones that he deserves an exalting unique to him. The highest word for valuing and exalting should be for God alone.
It's a relative word, so every one will have a god. That is because everyone values something. God is supposed to valued above all. If we value our caprice above all and make it the number one thing we prioritize, then per Quran, that is our god.
أَفَرَأَيْتَ مَنِ اتَّخَذَ إِلَٰهَهُ هَوَاهُ وَأَضَلَّهُ اللَّهُ عَلَىٰ عِلْمٍ وَخَتَمَ عَلَىٰ سَمْعِهِ وَقَلْبِهِ وَجَعَلَ عَلَىٰ بَصَرِهِ غِشَاوَةً فَمَنْ يَهْدِيهِ مِنْ بَعْدِ اللَّهِ ۚ أَفَلَا تَذَكَّرُونَ | Have you seen him who has taken his caprice to be his god and whom Allah has led astray knowingly, set a seal upon his hearing and heart, and put a blindfold on his sight? So who will guide him after Allah [has consigned him to error]? Will you not then take admonition? | Al-Jaathiya : 23
The believers loved God above all things:
وَمِنَ النَّاسِ مَنْ يَتَّخِذُ مِنْ دُونِ اللَّهِ أَنْدَادًا يُحِبُّونَهُمْ كَحُبِّ اللَّهِ ۖ وَالَّذِينَ آمَنُوا أَشَدُّ حُبًّا لِلَّهِ ۗ وَلَوْ يَرَى الَّذِينَ ظَلَمُوا إِذْ يَرَوْنَ الْعَذَابَ أَنَّ الْقُوَّةَ لِلَّهِ جَمِيعًا وَأَنَّ اللَّهَ شَدِيدُ الْعَذَابِ | Among the people are those who set up compeers besides Allah, loving them as if loving Allah—but the faithful have a more ardent love for Allah—though the wrongdoers will see, when they sight the punishment, that power, altogether, belongs to Allah, and that Allah is severe in punishment. | Al-Baqara : 165
In fact, believers prioritize the Prophet and his successors over themselves per 33:6. To prioritize God should mean we prefer striving in his path to the temporary pleasures of the life of this world:
قُلْ إِنْ كَانَ آبَاؤُكُمْ وَأَبْنَاؤُكُمْ وَإِخْوَانُكُمْ وَأَزْوَاجُكُمْ وَعَشِيرَتُكُمْ وَأَمْوَالٌ اقْتَرَفْتُمُوهَا وَتِجَارَةٌ تَخْشَوْنَ كَسَادَهَا وَمَسَاكِنُ تَرْضَوْنَهَا أَحَبَّ إِلَيْكُمْ مِنَ اللَّهِ وَرَسُولِهِ وَجِهَادٍ فِي سَبِيلِهِ فَتَرَبَّصُوا حَتَّىٰ يَأْتِيَ اللَّهُ بِأَمْرِهِ ۗ وَاللَّهُ لَا يَهْدِي الْقَوْمَ الْفَاسِقِينَ | Say, ‘If your fathers and your sons, your brethren, your spouses, and your kinsfolk, the possessions that you have acquired, the business you fear may suffer, and the dwellings you are fond of, are dearer to you than Allah and His Apostle and to waging jihad in His way, then wait until Allah issues His edict, and Allah does not guide the transgressing lot. | At-Tawba : 24
This is why Quran in several places says whoever desires the life of this world, will have nothing of the next, but the fire.
