35 One of them, a lawyer, asked him a question, testing him. 36 “Teacher, which is the greatest commandment in the law?” 37 Jesus said to him, “‘You shall love the Lord your God with all your heart, with all your soul, and with all your mind.’ 38 This is the first and great commandment. 39 A second likewise is this, ‘You shall love your neighbor as yourself.’ 40 The whole law and the prophets depend on these two commandments.” Matthew 22:35-40WEB
Jesus did not change the definition of love between the Old and New Testaments (see Matt. 5:17-19). Therefore, God's law in both Testaments teaches us the definition of "love."
Love -- the scriptural category -- is not merely an emotion. It is an evaluation of an action. In scripture, for example, "rebuking your neighbor" is a "loving" thing to do:
17 “‘You shall not hate your brother in your heart. You shall surely rebuke your neighbor, and not bear sin because of him. 18 “‘You shall not take vengeance, nor bear any grudge against the children of your people; but you shall love your neighbor as yourself. I am YHWH. Leviticus 19:17-18WEB
Physically chastising your child when they sin is a loving act:
24 One who spares the rod hates his son, but one who loves him is careful to discipline him. Proverbs 13:24WEB