For what if some did not believe? shall their unbelief make the faith of God without effect?

And he received the sign of circumcision as a seal of the righteousness that he had by faith while still uncircumcised. This was to make him the father of all who believe but are not circumcised, so that righteousness may be credited to them also.

For with the heart men believe and obtain righteousness, and with the mouth they make confession and obtain salvation.

As it is written, "Behold I put in Zion a stumbling stone, and a rock which shall make men fall. And none that believe on him, shall be ashamed."