JewishEncyclopedia.com - COVENANT "Eternal as the covenant with heaven and earth is God's covenant with the seed of Jacob (Jer. xxxiii. 25 et seq.). Christianity, however, interpreted the words of the prophet in such a way as to indicate a new religious dispensation in place of the law of Moses (Heb. viii. 8–13)."
Jewish Encyclopedia: New Testament: "The idea of the new covenant is based chiefly upon Jer. xxxi. 31–34 (comp. Heb. viii. 6–13, x. 16). That the prophet's words do not imply an abrogation of the Law is evidenced by his emphatic declaration of the immutability of the covenant with Israel (Jeremias 31:35–36; comp. Jeremias 33:25); he obviously looked for a renewal of the Law through a regeneration of the hearts of the people."
See Bruce M. Metzger's Textual Commentary on the Greek New Testament for details.
"Unlike Christianity, Judaism does not deny salvation to those outside of its fold, for, according to Jewish law, all non-Jews who observe the Noahide laws will participate in salvation and in the revards of the world to come". H. Revel, Universal Jewish Encyclopedia; Universal Jewish Encyclopedia Inc., New York, 1939–1943, pp. 227–228.
The reference here is to children that have not themselves made a profession of Christian faith. For those that hold the paedobaptist view, the reception of believers' children into the covenant, via baptism, typically happens before the child is even able to express faith (usually as an infant, hence the name).
Jewish Encyclopedia: New Testament: "The idea of the new covenant is based chiefly upon Jer. xxxi. 31–34 (comp. Heb. viii. 6–13, x. 16). That the prophet's words do not imply an abrogation of the Law is evidenced by his emphatic declaration of the immutability of the covenant with Israel (Jeremias 31:35–36; comp. Jeremias 33:25); he obviously looked for a renewal of the Law through a regeneration of the hearts of the people."
Jewish Encyclopedia: New Testament: "The idea of the new covenant is based chiefly upon Jer. xxxi. 31–34 (comp. Heb. viii. 6–13, x. 16). That the prophet's words do not imply an abrogation of the Law is evidenced by his emphatic declaration of the immutability of the covenant with Israel (Jeremias 31:35–36; comp. Jeremias 33:25); he obviously looked for a renewal of the Law through a regeneration of the hearts of the people."