Romans 4:11 And he received the sign of circumcision, a seal of the righteousness of the faith which he had yet being uncircumcised: that he might be the father of all them that believe, though they be not circumcised; that righteousness might be imputed to them also: Nave's Topical Index
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Of the Sacraments. ... faith is truth in performing promises, they have used it for ... shall the Lord not be able to stamp his creatures ... to circumcision, when he terms it a seal of the ... /.../the institutes of the christian religion/chapter 14 of the sacraments.htm