The Prophet ﷺ said, "Allah will say to that person of the (Hell) Fire who will receive the least punishment, 'If you had everything on the earth, would you give it as a ransom to free yourself (i.e. save yourself from this Fire)?' He will say, 'Yes.' Then Allah will say, 'While you were in the backbone of Adam, I asked you much less than this, i.e. not to worship others besides Me, but you insisted on worshipping others besides me.' " (Using translation from Bukhārī 3334)
"إِن الله تَعَالى يَقولُ لأهْوَنِ أهْلِ النار عَذابًا: لَوْ أنَّ لَكَ مَا في الأرْضِ مِنْ شَيء كنت تَفْتَدِى بِهِ؟ قَال نَعَمْ. قَال: فَقَدْ سَألتُكَ مَا هُوَ أهْوَنُ مِنْ هَذَا، وأنتَ في صُلبِ آدَمَ أن لا تُشْركَ بى فَأبَيتَ إِلا الشرْكَ".