Someone wrote that in his administrative duties, he had taken an action that fiercely angered one of his associates and turned him against him.
The Rebbe replied:
Bring into your heart a deep love for this man,
and his anger will spontaneously disappear.

G-d loves everyone equally, because each seemingly disparate soul develops individually as intended.
So there are many ways we interact with varying results. I made some enemies here and there, due to various disagreements at work, but I didn’t intend them to be personal (my job was Quality management) yet others did. (There is a lot more to the story of me.) So I didn’t have to develop love in my heart, as far as I know. I just let them be themselves and prayed. Letting yourself love the person will prevent more problems from your side.
If we think we control our bodies and others theirs, there will always be conflict. In that case we disconnect from our real Self, and that will force G-d to work at getting our attention and connecting rather than allowing Him to take care of our higher needs.