Love is part of our very being, and suits us better than hatred. To love your enemies, pray, try to see them as persons rather than objects of hatred, and see things from their perspective. With God’s help it is possible even for you! There are various parallels between the Church and the military[>M.1]. For example in the serious dedication to a common goal, a higher good.
We exist in virtue of our relationships with others. Serving the common good means serving yourself and others at the same time. Yes, it means giving something up, but it it will increase the happiness of the entire group. Jesus makes no clear distinction between serving others or yourself (Mt 7:12).