First of all, this is Paul who’s writing. You know, the Paul who identifies himself as a preacher and teacher (1 Tim. 2:7; 2 Tim. 1:11). This is the Paul who says that ‘Christ did not send me to baptize, but to preach the gospel (1 Cor. 1:17). This is the Paul, who when the Jews seek for a powerful sign and the Greeks seek for powerful wisdom, declares ‘we preach Christ crucified’ (1 Cor. 1:23). Paul is not really the sort of chap who downplays the Word in favour of something else. In fact, even when dealing with the gifts of the Spirit (which the people who use 1 Cor. 4:20 to downplay the Word would put in the category of powr), Paul is insistent that hearing the Word is of the utmost importance: ‘in the church I would rather speak five words with my understanding, that I may teach others also, than ten thousand words in a tongue’ (1 Cor. 14:19). So reading 1 Cor. 4:20 in a way that downplays the Word doesn’t sit comfortably at all in the wider context of Paul’s writing.
Secondly, look at the close context. What does he mean here by word and what does he mean by power. When Paul writes that ‘the kingdom of God is not in word but in power,’ the word that he’s talking about isn’t the word of God, but the word of puffed-up human wisdom. How do we know? Because he tells us in the previous verse: ‘But I will come to you shortly, if the Lord wills, and I will know, not the word of those who are puffed up, but the power’ (1 Cor. 4:19). Paul isn’t contrasting the Word of God with power at all; he’s contrasting human words with God’s power! That’s a very big difference.
Thirdly, where does Paul tell us the power of God is to be found? We don’t have to look far for the answer. By the time they’d read this far it would have been clear to the Corinthians. It is ‘the Word of the Cross’ which is ‘the power of God’ (1 Cor. 1:18). It is the preaching of Christ crucified which is the power of God (1 Cor. 1:23-24; 2:1-5). He writes the same thing in Romans as well (Rom. 1:16). Paul is adamant that true power is not found in human strength, but in the weakness of Christ. True power lies not in impressive rhetorical skill, persuasive arguments, or powerful signs, but in the weakness and death of the all-powerful God and our weak words about it, which he takes up as His powerful, life-giving words. True power is in the gospel. True power is in the preaching of the Word.
So really, 1 Cor. 4:20 means the opposite of what many people try to use it to mean. Paul isn’t downplaying the Word. No! He’s already established that the Word is the true power. And so when Paul writes – when the Holy Spirit through Paul writes – that ‘the kingdom of God is not in word but in power,’ he’s making it clear to us that God’s Kingdom doesn’t consist of and isn’t brought about by puffed-up human words, by human strength and wisdom, but rather it consists in, and is brought about by God’s power, which is the gospel Word of Christ and Him crucified. So ‘the kingdom of God is not in word but in power’ means that the kingdom of God is not in [human] power but in [God’s] Word.