Here is a link to my sermon for Palm Sunday.
I don't know if this sermon would qualify as a sermon on the subject of peace, but I think that it gives some insights as to why I think that peace is at the heart of the Christian faith.
The story of Jesus is the story of someone who turned upside down all of our usual values. In Holy Week, I think that we see this very starkly. Jesus could have been a conquering, military hero.
But, had he chosen this action that the world would have considered good - we love heros and hate wimps after all - there could have been no forgiveness. You can't forgive someone and crush them at the same time.
If we think that Jesus primary raison d'etre was forgiveness, then peace comes as part and parcel of that forgiveness. Not just the sort of preace that refrains from violence, either. But an all-encompassing peace. Shalom. The peace of God that passes all human understanding.
This is why I cannot separate "peace issues" from Christian theology.