A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z

Oathtaking

according to the Church's tradition, 2154
false, 2150-51
Jesus' words: "Do not swear at all," 2153
perjury, 2152, 2476
refusal to take an oath for trivial matters, 2155


Obedience

of the baptized to their calling, 1269
Christ's, 411, 475, 532, 539, 612, 615, 908, 1009
to conscience, 1790
to constituted laws, 2240
duty of, 1900
as an evangelical counsel, 915, 2053
of faith, 143, 144-49, 1831, 2087, 2098, 2135, 2340, 2716, 2825
as filial respect, 2216-17, 2251
and freedom, 1733
of priests, 1567
and sin, 1850, 1862, 2515
of the Virgin Mary, 148, 494, 511


Obligation

arising from the commandments, 2072
of bringing remedies to institutions and living conditions, 1888
to confess one's sins, 1457
of consecrated persons, 931
to defend one's nation, 2310
discharge from obligations linked to ordination, 1583
of justice, 2412, 2439, 2446
of lay people participating in the apostolate, 900
of obedience of faith, 2086-87
to observe the evangelical counsels, 915
to preserve the unity and indissolubility of marriage, 2364
to provide for the material needs of the Church, 2043
respect for the created world and obligation to future generations, 2456
to respond to divine charity, 2093
to sanctify Sundays and holy days, 2187
of seeking the truth and adhering to it, 2467, 2497
to take part in the liturgy on Sundays and holy days, 1389, 2180-83
See also Duty(ies)


Offering

of the Church, 1368, 1553
of the Eucharist, 1362, 1414, 2643
of Jesus, 529, 606-07, 610-11, 614, 616, 2824
of oneself, 459, 2031, 2711
of the Virgin Mary, 494, 2617, 2622


Offertory, 1333, 1350


Oil

consecration of, 1297
significance and use of anointing with, 695, 1183, 1237, 1241, 1289, 1293-94
See also Anointing; Chrism; Sacrament(s)


Old age. See the Elderly


Old Testament

canon of the Scriptures and, 120
catechesis reveals what is hidden under the letter of, 1094
fulfillment of promises and, 122, 528, 652, 1067
God the Father and the declared source of truth in the Old Testament, 684, 2465
the Holy Spirit and, 702
human illness and, 1502
juridical measures in, 2449
liturgy and, 1093, 1349
messiah in the Old Testament foretold by the prophets, 1286
mystery of the Church prefigured in, 753
mystery of the Trinity and, 237
prayer and, 2568, 2569, 2585, 2596, 2630
relation between the Old and the New Testaments, 128, 129, 140
sacred sign of life in, 2260
symbolic images in, 2130
theophanies of, 697
title "Son of God" and, 441
Trinity, its creative action and, 292
value of, 121
veneration of the Old Testament and its image, 61, 123, 138
See also Covenant, Old; Sacred Scripture


Omission

of caring for the sick, 2277
as a sin, 1853


One. See Church: attributes of the Church; God: titles and attributes of God


Oppression, 1739, 2243, 2448


Orbit. See Creation; Nature


Order

of creation, 299, 341, 1608
international, 1885
political, 2246
social or public, 1909, 1940, 2032, 2266-67, 2298, 2304, 2424


Organ transplants, 2296


Original sin

account of, 390
disobedience as the origin of, 215, 397-98
reason why God permitted, 412
significance of the doctrine of, 389
as the test of man's freedom, 396
transmission of original sin to all men, 404
as a truth of the faith, 388-89

consequences of original sin difficulty in knowing God, 37
        harmony destroyed, 400
        invasion of evil, 401
        loss of the grace of original holiness, 399
        in man's history, 402-06, 1250, 1607, 1609, 1707, 2259, 2515
        whole world held in the power of the evil one, 409


Orthodox churches

the "Creed" and, 247
unity of the Catholic Church and, 836


"Our Father," the prayer

at the center of the Scriptures, 2762-64
as the Church's prayer, 2767-72
as the Lord's Prayer, 2765-66

individual parts of "Our Father"
        "Father," 2779-85, 2798
        "Our Father," 2786-93, 2801
        "Who art in heaven," 2794-96, 2802
        "Hallowed be thy name," 2807-15, 2858
        "Thy kingdom come," 2816-21, 2859
        "Thy will be done," 2822-27, 2860
        "Give us this day our daily bread," 2828-37, 2861
        "Forgive us our trespasses," 2838-45, 2862
        "Lead us not into temptation," 2846-49, 2863
        "But deliver us from evil," 2850-54, 2864