Answ. 1. Church membership is the same thing in infants and in the adult.
2. Infants are naturally uncapable of doing all that in baptism which the adult must do; as to understand, profess, &c. themselves.
3. The baptism of the adult, being the most complete, because of the maturity of the receivers, is made the standing pattern in Scripture; for God formeth his ordinances to the most perfect ordinary receivers.
4. Though an infant be devoted acceptably to God by his parent's will, yet when he is at age it must be done by his own will.
5. Therefore a bare infant title ceaseth when we come to age, and the person's title ceaseth, unless it be renewed by himself, or his own consent. The reason is, because the conditions of his infant title then cease: for his parent's will shall go for his no longer.
6. Regularly and ad bene esse the transition out of the state of infant membership into the state of adult membership should be very solemn; and by an understanding, personal owning of the baptismal covenant.[302]
7. There needeth no other proof of this, than, 1. That God in Scripture never gave adult persons title to this covenant, but by their own personal consent; and at the first institution of baptism, both went together, (personal profession and baptism,) because the receivers were adult. 2. And that infants are capable of baptism, but not of personal profession. 3. Therefore though they are not to repeat baptism, which was done before, yet they are bound to make that profession at age which they never made before.
8. Where this solemn owning of their covenant cannot be had, (by reason of church corruptions, and magistrates' prohibition,) there the person's ordinary joining with the church, in the public profession and worship, is to be taken for an owning it.
9. He that being baptized in infancy, doth no way at full age own his baptismal covenant, is to be taken for an apostate: 1. Because his infant title ceaseth. 2. And he notoriously violateth his covenant. 3. Because he can be no adult christian that no way owneth Christ.
10. But this is to be understood of those that have opportunity; for one in a wilderness among heathens only, cannot join in public worship, nor give testimony of his christianity to the church.