Many in the religious world today claim for themselves additional infallible sources of information other than what is found in the Bible. Some of these religious groups claim that these additional sources are necessary because the Bible isn't a sufficient source of information for man's salvation. However, if it can be shown that inspired writers do, in fact, teach the sufficiency of the scriptures in supplying the necessary information for man's salvation, this means that other sources are not needed.
There are two ways that one could show that the scriptures supply all of the necessary information that man needs for salvation. One could either show where the scriptures directly say that they supply all of the information man needs, or one could show that in the entirety of the teaching of the scriptures, there is a complete picture given that would be sufficient for salvation. Because the later of these two would require a volume of information to prove, we'll focus upon the first method in this article.
The word “sufficient” means “adequate for the purpose; enough” according to the Random House dictionary. The American Heritage dictionary defines “sufficient” as “being as much as is needed.” Princeton University's WordNet defines “sufficient” in this way: “of a quantity that can fulfill a need or requirement but without being abundant.” So, in order for scripture to be sufficient for man's salvation it must be “adequate” to provide for man's salvation; it must be “enough” information, “as much as is needed,” or in a required quantity to fulfill the need. Does the Bible make such a claim for itself? There are several scriptures that answer this question.
Consider that the apostles themselves considered the written scriptures to be sufficient for providing for man's salvation. Romans 15:4 says, “For whatsoever things were written aforetime were written for our learning, that we through patience and comfort of the scriptures might have hope.” Paul says that the written scriptures are given that we might have hope for salvation. If they were not sufficient to provide for salvation, how could they provide hope? If the scriptures were less than sufficient to provide for salvation, they could not give hope. What kind of hope does the Christian have? Hebrews 6:19 says, “Which hope we have as an anchor of the soul, both sure and stedfast, and which entereth into that within the veil.” Such a hope is sufficient for salvation, hence, the scriptures that provide that hope, are sufficient for man's salvation.
Consider 1 Corinthians 15:1-4 which says, “Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures.” Paul tells the church at Corinth that the gospel he preached to them was sufficient to save them. What was the basis of that gospel? It was the death of Jesus for our sins, His burial, and resurrection. Paul makes it clear in this passage that these truths were “according to the scriptures.” It is sufficient for Paul that the scriptures declare, in prophecy, the gospel message sufficient for salvation. Were the scriptures sufficient to provide this information? They were. See also Romans 16:25-26.
In Acts 17:10, Paul and Silas made their way to Beroea. There they preached the gospel. Acts 17:11-12 says, “These were more noble than those in Thessalonica, in that they received the word with all readiness of mind, and searched the scriptures daily, whether those things were so. Therefore many of them believed; also of honourable women which were Greeks, and of men, not a few.” The Beroeans, prior to Paul and Silas' arrival were not believers. Paul and Silas then preached the gospel to them. What was said? Whatever it was, it caused the Beroeans to search the scriptures to see if what Paul said was true. When they looked to the scriptures, they believed and as a result became Christians. Did the scriptures supply that which was needed for salvation? They did.
Finally, however, we must look at 2 Timothy 3:14-17. Paul wrote to Timothy: “But continue thou in the things which thou hast learned and hast been assured of, knowing of whom thou hast learned them; And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus. All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, throughly furnished unto all good works.” Paul says several things here. First, he says that the scriptures were able to make Timothy wise unto salvation. Thus, they would be sufficient for man's salvation. Paul, however, doesn't stop his discussion here. He then says that the scriptures are given by inspiration; that is, they were given by the very breath of God. He then says that these scriptures are profitable for the purpose of making the people of God complete and that they furnish completely all the information one needs for all good works. In other words, there is not one good work in which man must be involved for salvation that the scriptures don't supply. They supply it all. Hence, the scriptures are sufficient for man's salvation.
In the story of the Rich Man and Lazarus (Luke 6:29-31), Abraham tells the Rich Man regarding the salvation of his brothers, “They have Moses and the prophets; let them hear them.” The Rich Man, in essence, objects and says that if only they had an additional source of information, they would believe. Abraham replied, “If they hear not Moses and the prophets, neither will they be persuaded, though one rose from the dead.” The implication is clear; the written word of God is sufficient to provide for man's salvation. Any information that one requires beyond that simply indicates unbelief.