Wherefore leaving the word, &c. This is to be taken as connected with what he had said in the last chapter, (ver. 12.) of the elements, or rudiments of Christian faith, concerning which, though some seemed not sufficiently instructed, yet he thinks it here enough to name them, and pass them over: to wit, 1. Penance, or the dispositions of a sincere repentance. 2. Faith, when they are come to the years of being instructed. 3. The doctrine of baptisms, which he expresseth in the plural number, either because all the faithful must be baptized once, if we speak of Christian baptism; or he means that persons ought to know they cannot receive Christ’s baptism over again. Or, in fine, he means that the baptisms used by the Jews, which they so frequently repeated, could not make them justified. 4. The doctrine of imposition of hands, by which is commonly expounded that which was given in the sacrament of confirmation. 5. Of the resurrection of the dead. 6. Of the judgment, by which God would judge all mankind. Of these things he supposeth them already instructed. (Witham)

We see here the order in which the apostles taught the Christian doctrine to the catechumens: 1. They excited them to sorrow for their sins. 2. They required of them acts of faith in God and his Son Jesus Christ. 3. They explained the nature of Christ’s baptism, its virtue, and difference from the baptism of John the Baptist and others. 4. After baptism, they laid their hands on them, that they might receive the strengthening grace of the Holy Ghost in confirmation; and finally, they excited them to perseverance, by the hope of a glorious resurrection, and of eternal life, and by setting before their eyes eternal damnation as the consequence of apostacy.