Infallibility is the doctrine that Holy Scripture is incapable of failing or deceiving—that it cannot lead astray in anything it teaches, but will infallibly accomplish the purpose for which God gave it. The two terms are closely related and often used together: inerrancy looks chiefly at the past and present, affirming that Scripture contains no errors; infallibility looks chiefly at Scripture’s power and reliability, affirming that it cannot err and cannot fail. Christ Himself grounded the term when He declared that the Scripture cannot be broken—it cannot be loosed, annulled, or proven false. God’s Word, He says through Isaiah, shall not return unto Him void, but shall accomplish that which He pleases and prosper in the thing whereto He sent it; grass withers and flowers fade, but the word of our God shall stand for ever. Infallibility therefore assures the believer not only that the Bible is true, but that it is utterly trustworthy as a guide—a sure foundation that will never collapse beneath him, a lamp that will never lead his feet into a pit. The Roman communion misappropriates the word, claiming infallibility for the church and the pope when defining doctrine; but Scripture lodges infallibility in the Word of God alone, to which church, council, and pope are all subject. The conscience may rest absolutely upon an infallible Scripture, for it shares the unfailing faithfulness of its Author.