IN THEIR OWN WORDS
AUTHORITY OF SCRIPTURENow all the doctrines in which the faithful are to be instructed are contained in the Word of God, which is found in Scripture and tradition.
Roman Catechism (1566), Introductory, "Study of the Word of God" (McHugh & Callan trans., 1923)
NATURAL / GENERAL REVELATIONThe latter, guided solely by the light of nature, advances slowly by reasoning on sensible objects and effects, and only after long and laborious investigation is it able at length to contemplate with difficulty the invisible things of God, to discover and understand a First Cause and Author of all things.
Roman Catechism (1566), Part I, Article I, "Knowledge of God More Easily Obtained Through Faith than Through Reason" (McHugh & Callan trans., 1923)
THE TRINITYIn the one Substance of the Divinity the Father is the First Person, who with His Only-begotten Son, and the Holy Ghost, is one God and one Lord, not in the singularity of one Person, but in the trinity of one Substance.
Roman Catechism (1566), Part I, Article I, "The Doctrine of the Trinity" (McHugh & Callan trans., 1923)
THE PERSON OF CHRISTWhile we thus acknowledge His twofold Nativity; we believe Him to be one Son, because His divine and human natures meet in one Person.
Roman Catechism (1566), Part I, Article II, "His Only Son" (McHugh & Callan trans., 1923)
ORIGINAL SIN & THE HUMAN WILLunhappy man went astray, and lost not only original justice, with which he had been supernaturally gifted and adorned by God, but also obscured that singular inclination toward virtue which had been implanted in his soul.
Roman Catechism (1566), Part IV, The Third Petition, "Man's Proneness to Act Against God's Will" (McHugh & Callan trans., 1923)
THE NATURE OF SAVING FAITHA lighted taper is then put into the hand of the baptised to signify that faith, inflamed by charity, which is received in Baptism, is to be fed and augmented by the exercise of good works.
Roman Catechism (1566), Part II, Baptism, Ceremonies of Baptism, "The Lighted Candle" (McHugh & Callan trans., 1923)
JUSTIFICATIONOur souls are replenished with divine grace, by which we are rendered just and children of God and are made heirs to eternal salvation.
Roman Catechism (1566), Part II, Baptism, Effects of Baptism, "Third Effect of Baptism: Grace of Regeneration" (McHugh & Callan trans., 1923)
EXTENT OF THE ATONEMENTFor if we look to its value, we must confess that the Redeemer shed His blood for the salvation of all; but if we look to the fruit which mankind have received from it, we shall easily find that it pertains not unto all, but to many of the human race.
Roman Catechism (1566), Part II, The Eucharist, "Explanation of the Form Used in the Consecration of the Wine" (McHugh & Callan trans., 1923)
PERSEVERANCE & ETERNAL SECURITYAs he who suffers shipwreck has no hope of safety, unless, perchance, he seize on some plank from the wreck, so he that suffers the shipwreck of baptismal innocence, unless he cling to the saving plank of Penance, has doubtless lost all hope of salvation.
Roman Catechism (1566), Part II, Penance, "Importance of Instruction on this Sacrament" (McHugh & Callan trans., 1923)
INDWELLING OF THE HOLY SPIRITBy this we are given to understand that to those who are baptised are imparted the gifts of the Holy Spirit, that to them are opened the gates of heaven.
Roman Catechism (1566), Part II, Baptism, "Effects of Baptism Foreshadowed in the Baptism of Christ" (McHugh & Callan trans., 1923)
SPIRITUAL WARFAREThe third order is that of exorcists, to whom is given the power to invoke the name of the Lord over those who are possessed by unclean spirits.
Roman Catechism (1566), Part II, Holy Orders, "Exorcist" (McHugh & Callan trans., 1923)
BAPTISMIf then, through the transgression of Adam, children inherit original sin, with still stronger reason can they attain through Christ our Lord grace and justice that they may reign in life.
Roman Catechism (1566), Part II, Baptism, Necessity of Baptism, "Infant Baptism: Its Necessity" (McHugh & Callan trans., 1923)
THE LORD'S SUPPERThis conversion, then, is so effected that the whole substance of the bread is changed by the power of God into the whole substance of the body of Christ, and the whole substance of the wine into the whole substance of His blood, and this, without any change in our Lord Himself.
Roman Catechism (1566), Part II, The Eucharist, "Transubstantiation a Total Conversion" (McHugh & Callan trans., 1923)
THE FINAL STATE OF THE LOSTWhen, moreover, we reflect that this torment is to be eternal, we can see at once that the punishment of the damned includes every kind of suffering.
Roman Catechism (1566), Part I, Article VII, "The Sentence of the Wicked" (McHugh & Callan trans., 1923)