It’s important to define terms. What does “love” mean?
There are different kinds of love we experience. There’s love for children, parents, other relatives, close friends, etc. Which type of love are we obligated to feel towards another Jew not in one of the aforementioned categories?
Rabbi Dessler, zt”l, in “Michtav m’Eliyaju” writes that the best way to to come to love another Jew is to help them. By investing one’s self in the advancement and development of another, one comes to love the recipient of those efforts. In a much smaller scale, he suggests that this is a component of the parent-child bond.