How does Works of Love distinguish neighbourly love from friendship and romantic love?

In Works of Love, Søren Kierkegaard distinguishes neighbourly love from friendship and romantic love by focusing on the nature of the motivation and the scope of the relationship.1

Kierkegaard categorizes friendship and romantic love as "celebrated loves" that are inherently spontaneous and preferential. These forms of love arise naturally from personal inclination, attraction, or desire for a specific individual, leading him to classify them as forms of "self-love"—or the "self-love of the 'We'"—because they are exclusionary and limited to those who satisfy one's personal preferences.1

In contrast, neighbourly love is defined by the following characteristics:

• Commanded, not spontaneous: Because it does not arise from natural inclination, it must be commanded by God.1
• Non-preferential: It does not require the other person to be attractive or part of one's own social, familial, or national group.1
• Universal: It extends to all, including one's enemies, as the neighbour is defined as any human being rather than a chosen companion.1

Ultimately, Kierkegaard argues that while society celebrates the exclusivity of friendship and romance, only the Christian command to love the neighbour transcends these self-centered boundaries.1