The Responsorial (Psalm 18) pinpoints the focus of all religion: “I love you, Lord”; then adds: “my strength.”
Deuteronomy 6: 4-13 gives us what Jesus called “the greatest and first commandment” — “You shall love the Lord your God with all your heart, and with all your soul, and with all your strength.” This is the essence of religion: to love God, not as the first among those whom we love, but as the All. We are to love God with our whole heart. That love is not divided with anyone. It is unique, the all-embracing response of our being, whole and entire. It is not shared. Nothing is in competition with it. It is absolute: “The Lord is our God, the Lord alone!” We obey God alone; fear God alone; live for God alone. We live only for God: to know, love and serve him.
To love anything or anyone alongside of God is idolatry. Our love for God must not be divided. As God is One, our love for him must be one. This does not diminish our love for other people or values; it relocates it. Anything or anyone else we love we must love in God; not alongside of God or in addition to God, but as included in our love for God. The truth is, no creature has any being or goodness except through God’s presence in it. So any goodness we recognize in anyone, we must recognize as a participation in God’s goodness. People are in the image of God. What we see and love in them is their likeness to God. We love God in them and them in God. “I love you, Lord, my strength” — and “my everything else!” To choose anything in violation of God’s will is simultaneously to reject the ultimate reality of the very good we desire.
Matthew 17: 14-20 raises a question: Christ’s disciples could not heal the boy who kept “throwing himself into fire and water.” Why has the Church not been able to heal society of its destructive pattern of throwing itself into the “fire and water” of selfish exploitation, divisions and bloody violence? Jesus’ answer is, “Because of your little faith.”
In the context (see Matthew 16: 21-23; 17: 10-13 and 22-23), Jesus may be referring specifically to our rejection of his “new commandment” to love one another as he himself loved us on the cross. Until we are willing to lose our lives in love for our enemies instead of taking their lives in self-defense or in the defense of our country and our cherished way of life, we, as Peter did, are rejecting the way of unrestricted love that is the only salvation of society and of the world. To “take up the cross” means to respond with love to whatever anyone does to us. Any other response leads us into the “culture of death.
Christians who kill in war or self-defense are not sufficiently instructed to be guilty, since after the fourth century Church authorities (reverting to Peter’s “human way” of thinking rather than divine?) have accepted the “just war theory,” with the result that Catholic nations have been slaughtering each other — “throwing themselves into fire and water” —in savage wars ever since.
St. Thomas Aquinas accepted the “just war theory” — for laity, but not for ordained priests! When you read his arguments, remember that in his day the laity were not thought to be called to perfection as Vatican II has now made clear they are. And the laity were excluded from that “full, active, conscious participation” in the Eucharist that the Church is calling for so emphatically today. Aquinas seems to be saying is that warfare and the Eucharist are incompatible, but that only ordained priests are sufficiently involved in the Eucharist for it to make any difference! His text follows:
Now warlike pursuits are altogether incompatible with the duties of a bishop and a cleric, for two reasons. First, because, warlike pursuits are full of unrest, so that they hinder the mind very much from the contemplation of Divine things, the praise of God, and prayers for the people, which belong to the duties of a cleric.... The second reason is a special one, because all the clerical Orders are directed to the ministry of the altar, on which the Passion of Christ is represented sacramentally, according to 1Corinthians 11:26: "As often as you shall eat this bread, and drink the chalice, you shall show the death of the Lord, until He come." Wherefore it is unbecoming for them to slay or shed blood, and it is more fitting that they should be ready to shed their own blood for Christ, so as to imitate in deed what they portray in their ministry....
The internet source article continues:
Most fascinating in Aquinas’ defense of the ban on clerical killing is that today—when the Church upholds a universal call to holiness in which all are called to perfect love in Christ—his reasons suggest that any serious follower of Jesus ought not shed blood.
For example, Aquinas writes, “it is more fitting that they should be ready to shed their own blood for Christ, so as to imitate in deed what they portray in their ministry.” (Summa II-II 40.2). Also, they “should imitate their master” who “when He was struck did not strike” (II-II 64.4). We should look at these teachings and reconsider who the “they” might be.
John Paul II, who seems to accept the “just war,” nevertheless insisted on the same radical love when speaking of the doctrine of the cross. For Christians, he says, life “finds its… meaning and its fulfillment when it is given up” in love for others. He says this is the way we “realize in the fullness of truth the meaning and destiny of our existence.” To renounce the right to self-defense, he tells us, is an
act of “heroic love which deepens and transfigures the love of self into a radical self-offering, according to the spirit of the Gospel Beatitudes (cf. Matthew 5:38-40). The sublime example of this self-offering is the Lord Jesus himself.”
Since John Paul has proclaimed repeatedly that “Jesus’ way of acting and his words, his deeds and his precepts constitute the moral rule of Christian life,” and that “Christ’s example, no less than his words, is normative for Christians,” he is obviously proposing this heroic love as the normal standard of virtue for Christians to strive to embrace. This vocation to give oneself in perfect love for others, John Paul tells us, is expressed in every Eucharist we celebrate.
This should give us matter for thought at Mass, especially during the Eucharistic Prayer!
Initiative: Be a priest. Love back, no matter what is done to you.
 Matthew 22:38.
 John 13:34. See John Paul II, The Gospel of Life, nos. 12, 24.
 Summa Theologica II-II 40.2, quoted from “Aquinas the Peacenik?” www.catholicpeacefellowship.org.
 See The Gospel of Life, nos. 22, 25, 34, 39, 40, 47, 51, 52 to 57; The Splendor of Truth, nos. 18 to 21, 107; “World Day of Peace” address, Jan. 1, 1993.