The phrase ‘the sufficiency of Scripture’ emphasises that the Holy Scriptures of the Old and New Testaments are the complete and sufficient revelation of God for all mankind. The term represents the truth behind the affirmation of Psalm 19:7: ‘the law of the Lord is perfect’. It is also implicit in the rejection of all other sources of revelation in Isaiah 8:20 ‘To the law and to the testimony; if they speak not according to this Word, it is because there is no light in them’.
This doctrine, expressed in the Latin phrase Sola Scriptura, lay at the heart of the Protestant Reformation and it remains a fundamental element of historic evangelical Christianity. Calvin’s confession of faith for the church in Geneva gives clear expression to this fact. ‘We confess our faith based alone on the Holy Scriptures, without any additions from human wisdom: to desire as the only doctrine for our spiritual welfare the Word of God, without diminution or addition, according to the command of our Lord’.
This conviction about the ‘sufficiency of Scripture’ marks a significant point of division among professing Christians, and many are critical of it for this reason. It is therefore necessary to demonstrate that we derive this doctrine, as all other Christian doctrines, from the Bible itself. Our aim will be to discover and express the testimony of Scripture to itself.
The nature of Holy Scripture
We may begin with the affirmation that there is nothing more fundamental and essential to Christianity than the inspired and infallible Holy Scriptures, received as the Word of the true and living God. A most familiar and important text is 2 Timothy 3:16-17: ‘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, thoroughly furnished unto all good works’.
The words ‘given by inspiration of God’ actually translate a single adjective in the original Greek text, namely, a word that can be rendered ‘God-breathed’. This indicates that the very words of Holy Scripture had their origin in the mind of God, and were communicated by him to his chosen human servants. They then spoke and wrote what the Lord their God had revealed to them.
Furthermore, the writers were empowered by the Holy Spirit in the actual writing of these words, as is described in 2 Peter 1:21: ‘Men spoke from God as they were carried along by the Holy Spirit’. Accordingly, the words recorded in the Scripture are often affirmed to be the actual words of God – the expression ‘Thus saith the Lord’ occurs over 700 times in the prophetic writings. Again, in Hebrews 3:7, the words of Psalm 95:7-11 are directly attributed to the Holy Spirit – ‘as the Holy Spirit says’. As a further example, Paul introduces a quotation from Isaiah 6 with the words, ‘the Holy Spirit spoke the truth’ (Acts 28:25). In 2 Samuel 23:2 David claimed, ‘The Spirit of the Lord spoke through me; his word was on my tongue’.
There are two necessary implications of this affirmation about Scripture.
The first implication is that the Holy Scriptures are completely true. We can demonstrate this point explicitly from many available passages. In 1 Samuel 15:29, for example, the prophet Samuel teaches the erring King Saul that the Lord, ‘who is the glory of Israel, does not lie’, meaning that God’s words are true. In Titus 1:2 we are informed that God does not (or cannot) lie, and the Greek adjective used in the original means that God is free from falsehood and thus completely truthful.
Our Lord Jesus, in prayer to his Father, affirms this attribute of Scripture: ‘Your word is truth’ (John 17:17). It can surely be held as virtually self-evident that God the Father is ‘the God of Truth’. He is the truth-loving and the truth-speaking God.
The Son of God declared concerning himself, ‘I am the Truth’, and elsewhere asserted that the Holy Spirit is ‘the Spirit of Truth’ (John 14:6, 17). It is impossible to conceive (and abhorrent to consider) that the Triune God could ever communicate error; for all falsehood has its origin with the Devil, in whom there is no truth (John 8:44). Our Lord Jesus in Revelation 22:15 made this solemn statement: ‘Everyone who loves and practises falsehood’ is excluded from heaven.
The second implication is that the Scriptures are authoritative. This follows because the authority of any writing resides in the author! Almighty God, who created the heavens and the earth, and who commands the obedience of all created beings, is the God who speaks with absolute authority in his written word. He thereby exercises his inherent right to command the total obedience of mankind.
Further, since the Son of God is the Lord and supreme Head of the church, there is the absolute necessity that the church should be subject to his Word. Here we have the basis of scriptural reformation as acknowledged by Martin Luther, both for the individual Christian and the whole church.
For himself he insisted, ‘my conscience is subject to the Word of God’, and he based his ministry on this principle. ‘The Scripture ought to rule, and all ought to obey and be subject unto it’, he declared. Teachers and preachers in the church, he insisted, ‘ought not to be masters, judges, or arbiters, but only witnesses, disciples and confessors of the Scripture’.
The rule of Faith
It is this conviction that undergirded the revival of biblical Christianity in the sixteenth and seventeenth centuries, and found expression in its creeds and confessional statements. Thus, for example, in the Westminster Larger Catechism, Answer 3, we read: ‘The Holy Scriptures of the Old and New Testaments are the Word of God, the only rule of faith and obedience’.
Surely this assured knowledge that God himself has spoken, and provided in his Word the infallible record of his self-revelation, should evoke from us the due and thankful response of humility and obedience. We should reverence the Scriptures because they are the direct expression of God’s mind and will and proceed from him alone. They have nothing that is merely human contained within them.