This article, "Jihad, the Lord's Supper, and eternal life" may seem a bit random in its inclusion on this blog, but I got to it after following a link, to another article by the same Spengler, provided by a commenter below.
In a world of conflict and competition for attention, Christians need to have a grasp of the big picture of theology ... and of anti-theologies, or, if you prefer, rival theologies. I find Spengler good on the big picture. Here's an excerpt:
"But what is it that God demands of us in response to our demand for eternal life? We know the answer ourselves. To partake of life in another world we first must detach ourselves from this world in order to desire the next. In plain language, we must sacrifice ourselves. There is no concept of immortality without some concept of sacrifice, not in any culture or in any religion. That is a demand shared by the Catholic bishops and the Kalahari Bushmen.
God's covenant with Abraham is unique and singular in world history. A single universal and eternal god makes an eternal pact with a mortal that can be fulfilled only if Abraham's tribe becomes an eternal people. But the price of this pact is self-sacrifice. That is an existential mortal act beyond all ethics, as Soren Kierkegaard tells us in Fear and Trembling. The sacraments of revealed religion are sublimated human sacrifice, for the revealed god in his love for humankind spares the victim, just as God provided a ram in place of the bound Isaac on Mount Moriah. Among Jews the covenant must be renewed in each male child through a substitute form of human sacrifice, namely circumcision.  Christians believe that a single human sacrifice spared the rest of humankind.
Jihad also is a form of human sacrifice. He who serves Allah so faithfully as to die in the violent propagation of Islam goes straight to paradise, there to enjoy virgins or raisins, depending on the translation. But Allah is not the revealed god of loving kindness, or agape, but - pace Benedict - a god of reason, that is, of cold calculation. Islam admits no expiatory sacrifice. Everyone must carry his own spear.
We are too comfortable, too clean, too squeamish, too modern to descend into the terrible space where birth, death and immortality are decided. We forget that we cannot have eternal life unless we are ready to give up this one - and this the Muslim knows only through what we should call the sacrament of jihad. Through jihad, the Muslim does almost precisely what the Christian does at the Lord's Supper. It is the sacrifice of Jesus that grants immortal life to all Christians, that is, those who become one with Jesus by eating his flesh and drinking his blood so that the sacrifice also is theirs, at least in Catholic terms. Protestants substitute empathy identification with the crucified Christ for the trans-substantiated blood and flesh of Jesus."