And His—exalted is He—statement: “Among people are those who take equals apart from Allah; they love them as they should love Allah. But those who believe are stronger in their love for Allah. If only the wrongdoers could see—when they behold the punishment—that all power belongs to Allah entirely, and that Allah is severe in punishment.” ⦗al-Baqarah 165⦘

Of mankind: a group of people.
Apart from Allah: meaning other than Allah.
Equals: counterparts and rivals.
They love them: love is the inclination toward what one perceives—or thinks—to be good, coupled with eagerness for it.
As they love Allah: they put them on the same footing as Him in the love that entails humiliation before and submission to the beloved.
If only they could see: i.e., if they but knew.
When they behold the punishment: at the very moment they witness it.
That all power belongs to Allah: for might and dominance are His alone.

Overall meaning of the verse: Allah, majestic is He, describes the state of the polytheists in this world and their end in the Hereafter: they set up for Allah equals and rivals, matching them with Him in love. He then mentions the believers, the monotheists; they love Allah with a love that surpasses the love the idolaters have for their partners—or even surpasses the idolaters’ love for Allah—because the believers’ love for Allah is pure, whereas the idolaters’ love for Him is shared with others. He then threatens these idolaters, declaring that if they only knew what they will witness on the Day of Resurrection and the dreadful fate and severe punishment that will befall them for their polytheism, and that Allah alone possesses power and supremacy