To grasp the power of God’s word, it is helpful to review a few passages of Scripture in which that power is set forth with particular clarity.
In Genesis 1:1–31, we repeatedly read statements like, And God said, 'Let there be...'
And whenever God speaks, there is a corresponding effect in the created universe: And there was light...and it was so.
Thus we see how the entire created order came into being by the power of God’s word: God spoke and it was so.
When God led Ezekiel into the valley of dry bones, he asked the prophet, Son of man, can these bones live?
By any human measure it was impossible. Yet God told Ezekiel to prophesy to the bones and to say to them, O dry bones, hear the word of the Lord! Thus says the Lord GOD to these bones: Behold, I will cause breath to enter you, and you shall live
(Ezekiel 37:4–5, emphasis added). Ezekiel records his experience in these words: So I prophesied as he commanded me, and the breath came into them, and they lived and stood on their feet, an exceedingly great army
(Ezekiel 37:10). Once again we see how God acted in power through his word.
For Paul, the creation account provides the pattern by which God’s saving power operates in the lives of those whose minds are darkened by Satan: For God, who said, 'Let light shine out of darkness,' has shone in our hearts to give the light of the knowledge of the glory of God in the face of Jesus Christ
(2 Corinthians 4:6). It is when God speaks that reality changes.
In the case of the Thessalonian Christians themselves, the power of God’s word had turned them from idols to serve the living and true God, even though their conversion entailed severe persecution (1 Thessalonians 1:5–6, 1 Thessalonians 1:9–10). The word continued to work in them as the Spirit taught them to love one another and to conform their lives to the pattern of Christ (1 Thessalonians 4:9–10).
13 And we also thank God constantly for this, that when you received the word of God, which you heard from us, you accepted it not as the word of men but as what it really is, the word of God, which is at work in you believers.