A week ago, in last Sunday’s Gospel, on the mountain, Jesus announced that Peter
was “blessed” because the Father had revealed to him that Jesus was “the Messiah and
the Son of the living God” (Matthew 16:17). Jesus declared that Peter would be the
rock on which Jesus would build His church (Mt 16:18).
Yet, in our Gospel, for today, Matthew 16:21-27, Jesus scolds Peter and warns him to
get behind him because he speaks like Satan. What happened?
St. Thomas Aquinas wonders how, at one moment, Peter could have been such a clear
idea of Jesus’ identity and then, shortly afterwards, completely misunderstand Jesus’
mission.
Thomas finds the answer in an explanation of St. John Chrysostom that Jesus wished
to show Peter what he could do by himself and what he could do by the grace of God.
Through grace, Peter realized that Jesus was the Son of God but when God withheld
His grace, Peter fell back into his old ways of thinking. God allows people to fall so that
they may know their humanness as well as their need for grace (Commentary on the
Gospel of Matthew).
Jesus believed that He must suffer and be put to death. There are many important
explanations, but the essential one is that Jesus saw His dying as an act of love: “No
one has greater love than to lay down his life for his friends” (Jn 15:13).
Thomas recalls that Jesus’ death was understood as a sacrifice by the Letter to the
Ephesians, “Live in love, as Christ loved us and handed Himself over for us as a
sacrificial offering to God for a fragrant aroma” (Eph 5:2).
Thomas points out John Chrysostom’s attention to voluntary following of Jesus, “who
wishes,” which is greater than being forced. One who follows Christ “ought to be ready
to suffer whatever whatsoever death on account of God. To suffer on account of one’s
sins is shameful: but to suffer for God’s sake is not shameful” (Commentary on the
Gospel of Matthew).
Thomas reflects: “It is as though He were to say, ‘It is necessary that you be prepared to
imitate Christ’s Passion.’ Martyrs corporally imitate the Passion in a special way, but
spiritual men imitate it spiritually, by spiritually dying for Christ” (Commentary on the
Gospel of Matthew).
How can we die spiritually? Thomas recalls the teaching of Gregory the Great on
“spiritual mortification,” that the one who would follow Jesus must first of all, die to sin:
“You too must think of yourselves as dead to sin and living for God in Christ Jesus”
(Rom 6:11).

Another form of self-denial is to give up one’s own will: “For I, through the law, am dead
to the law, that I may live to God; with Christ I am nailed to the cross” (Rom 2:19). If we
realize that God is acting in our lives as He acted in Jesus’ life, we must be ready to
accept our lives as they unfold.
Being “nailed to the cross” with Christ doesn’t only mean physical sufferings, although
many people do suffer physically. Thomas connects the Latin word for “cross,” Crux,
with the Latin word Cruciatus, meaning “tormented.” Thomas relates them through
compassion: “A man is spiritually tormented whose mind is tormented on account of his
compassion for his neighbor as the Apostle Paul says: ‘Weep with those who weep”
(Rom 12:15).
Jesus declares: “Whoever would save his life will lose it, but whoever loses his life for
My sake will find it. For what does it profit a man, if he gain the whole world and suffer
the loss of his own soul Or what exchange shall a man give for his soul?” (Mt 16:25-26).
Thomas comments that there is a well-being of the soul and a well-being of the body. A
person will sacrifice the means for something more important, as when a person spends
his money on his health. So the soul is more important than the body and the person
should be ready to give up things for the body for the sake of the soul.
Jesus calls us away from what St. Catherine of Siena called “selfish self-love,” not that
we shouldn’t love ourselves or our bodies. According to St. Thomas, we should love
ourselves as belonging to God: “Among these things which he loves out of charity
because they pertain to God, he loves also himself” (2a2ae. 25, 4).
In a similar way, St. Thomas emphasizes that our bodies are basically good: “The
nature of the body was created, not by an evil principle, as the Manichean pretend, but
by God… Consequently, out of the love for charity with which we love God, we ought to
love our bodies also…” (2a2ae. 25, 5).
Related to our bodies, in the second reading for today, St. Paul speaks of offering our
bodies to God as a sacrifice: “I beg you through the mercy of God to offer your bodies
as a living sacrifice, holy and acceptable to God, your spiritual worship” (Rom 12:1).
According to St. Augustine, a visible sacrifice is a sign of an invisible sacrifice offered to
God. Sacrificing our bodies is tied in with our interior sacrifice of ourselves. We do this
first of all by sacrificing our soul: “The sacrifice acceptable to God is a contrite spirit” (Ps
51:17).
A person also makes a sacrifice by giving to the poor: “Do not neglect to do good and to
share what you have, for such sacrifices are pleasing to God” (Heb 13:16).
A person sacrifices himself when he or she suffers for God, as Christ did: “He gave
Himself up for us, a fragrant offering and sacrifice for God” (Eph 5:2). Paul speaks of his

being poured out for the Christians: “Even if I am to be poured as a libation upon the
sacrificial offering of your faith, I rejoice” (Phil 2:17).
Thomas notes that Paul spoke of a “living sacrifice,” which means that it is more than an
external action: “That the offering we make to God of our body be living by faith
transformed by love: ‘the life I now live in the flesh I live by faith in the Son of God’ (Gal
2:20) (Commentary on Romans, 960).
Paul speaks of the sacrifice as “holy.” In the Old Testament, the act of sacrificing made
an object holy: “The sacrificial offering presented to God was sanctified in its very
immolation… Therefore, Paul adds ‘holy,’ made so by the devotion with which we bind
our bodies to the service of God: ‘Consecrate yourselves, therefore, and be holy,
because I the Lord your God am holy’ (Lev 20:7). Holiness in the proper senses is a
relation to God, insofar as one does what is just before God” (Commentary on Romans,
961).
“For a man’s good and his justice consists mainly in the internal acts, by which he
believes, hopes, and loves. Hence it says in Luke, ‘the kingdom of God is within you’ (Lk
17:21). For it does not consists principally of exterior works, as is said ‘the kingdom of
God is not food and drink’ (Rom 14:17). Hence, internal acts stand as an end sought for
its own sake, whereas external acts, in which our bodies are presented to God, stand as
means to an end”
“No limit is set on something set as an end; rather, the greater it is the better it is. But on
what is sought as a means to an end, a limit is set in accord with its proportion to that
end. Thus, a doctor seeks as much health as possible, but he does not give as much
medicine as he can; rather, he limits it to the amount required for restoring health.
Similarly, person should set no limit to his faith, hope, and love; rather, the more he
believes and hopes and loves, he better he is. Hence it is said in Deuteronomy, “You
shall love the Lord your God with all your heart’ (Deut 6:4).”
“But in external acts a discreet limit is imposed by the requirements of love. Hence
Jerome says: ‘Does not rational man lose his dignity, if he chooses to fast and watch at
the expense of his bodily health or incur the marks of madness or sadness from singing
the Psalms and office” (Commentary on Romans, 964).
Denis Vincent Wiseman, O.P.
References to St. Thomas Aquinas’ Commentary on the Gospel of St. Matthew are
taken from the translation of Fr. Paul M. Kimball, published by Dolorosa Press in 2012,
pp. 569-677.
References to St. Thomas Aquinas’ Commentary on Romans were taken from the
translation begun by Fr. Fabian R. Larcher, O.P. and edited by J. Mortensen and E.
Alarcón. The translation was published by the Aquinas Institute for the Study of Sacred
Doctrine, Lander, Wyoming, in 2012.