This kind of love is difficult. It is unnatural. Which is why we can't conjure it up. This kind of love is a result of living in the Spirit.
43“You have heard that it was said, ‘ You shall love your neighbor and hate your enemy.’ 44 But I say to you, love your enemies and pray for those who persecute you, 45 so that you may be sons of your Father who is in heaven; for He causes His sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous. 46 For if you love those who love you, what reward do you have? Do not even the tax collectors do the same? 47 If you greet only your brothers, what more are you doing than others? Do not even the Gentiles do the same? 48 Therefore you are to be perfect, as your heavenly Father is perfect. (Matthew 5)
Do not be overcome by evil, but overcome evil with good. (Romans 12:21)
I often think, "but they don't deserve love, God!" He quickly reminds me that I didn't deserve it either. I remember when Hussein and Bin Laden were killed, and I (along with the rest of the US) rejoiced. Hussein and Bin Laden didn't deserve to be loved, but it doesn't mean that I shouldn't love them. It was hard to imagine loving those men, but that is what God commands. They deserved death . . . so do I. It is easy to love people who are kind and loving. Loving people like these men, or just the person who says false things about you, this is love that only comes from God.
We love, because He first loved us. (I John 4:19)
Watch over your heart with all diligence, For from it flow the springs of life. (Proverbs 4:23)
Love is good . . . it is a result of living in the Spirit. So spend time in the Spirit more and more every day, so that love for people flows out of us.