to love: to value someone or something so highly that you act for their good and hold to them
This is the New Testament's main word for love. At its heart it is not a feeling that washes over a person but a settled regard that treats someone as precious and seeks their good, whatever the cost. That is why it can be commanded: you are told to love your neighbor, and even your enemy, which would make little sense if the word named only an emotion you cannot summon at will.
The same word covers the whole map of love. It names God's love for the world and for his Son, a person's love for God, love between husband and wife, love for neighbor and for enemy, and the love Christians owe one another. The writers, above all John and Paul, made it the signature word for the self-giving love shown at the cross, where God gives up what is most precious for people who had not earned it.
The one place the meaning seems to turn is when the object is wrong. The same act of treasuring something and clinging to it becomes a fault when the thing loved is darkness, money, human praise, or the present world. The word itself does not change; what changes is whether the thing held so dear is worth loving. So loving the wrong thing is condemned in the very terms that loving God is praised.