Excellent sermon by the youth pastor today about loving our enemies. (My eldest thinks he is learning to preach well because youth leaders have to think about their audience rather than just talk out loud to the section of the congregation most like themselves.) The strength of it was his focus on noticing the enemies close by. Jesus's examples were very individual, of an enemy that strikes you or steals from you. Whatever Jesus thought his followers should think about the fortunes of Romans or Greeks in general He doesn't say.
The sermon did include the usual extension of feeling enmity toward ISIS, and what should follow from that. That is what anyone who has been to seminary was immersed in, and likely still is with his peers he keeps in contact with from those days, or his new peers in the clergy. But that was not the center of the homily. The center was those who had hurt you, those who you can hardly bear to think about, those who are or were quite near to you.
If I say "ISIS is our enemy, we should love them and pray for them," what changes in my life, really? At most, it might change who I vote for - which, you may remember - I regard as a largely symbolic act of personal signalling. The difficulty arises from our usual use of the word enemy. Our immediate though is of a national enemy, then perhaps another group within our own borders. We don't easily remember that our real enemies are among us, at our jobs or under our roofs, or at minimum, at our weddings, reunions, and funerals. We have to be reminded by someone else.
It sounds as if it was the same in Jesus's day, as he has to mention it specifically in Matthew 10:36, A person's enemies will from their own household.
I have given up alcohol for Lent, and use the momentary discomfort of thinking a glass of wine or a scotch-on-the-rocks might be nice to pray for an enemy in the family, who is also a friend. In most liturgical traditions, a prayer focus on another person (not cause) used to be common in Lent. That is where those painted eggs in the Orthodox traditions come from: each was crafted for a specific person by the one who had prayed for him or her of Lent.
Note on giving up stuff: We are physical creatures and we need to enlist our bodies in our spiritual practice, not pretend they are not there because we are too spiritual. Another note on giving up stuff: I have also cut way back on starches because I love them. I find it is easier to give up two things than one, somehow.