Consideration of the character of the Christian religion shows there will always be a place for full-time ministry of the word of God. The Christian religion is a religion of faith in Christ the Lord. Faith is distinguished from superstition by being based on the truth and distinguished from rashness by bgeing based on the knowledge of the thruth. All this depends on true taching, for we are not born with a knowledge of the truth. Moreover, Christianity is a religion of personal relationship, that of fellowship. Fellowship only comes through hearing and responding to a word spoken. God relates himself to us speaking thorugh his word and we relate to him by responding to his word. So it is plain that a ministry which conveys and makes clear the truth about God and conveys God’s word to the mind and so to the conscience of the hearer is an essential characteristic of Christianity. If this ministry dies out then Christianity dies out.
The same conclusion may be arrived at from a slightly different approach. Jesus Christ is Lord but he can exercise no Lordship nor can obedience be the response of the Christian unless the mind of Christ is known and known relevantly to the circumstances of the Christian. This again requires a teaching ministry which understands the mind of Christ and how it applies to modern circumstance and which accompanies this teaching with exhortation and admonition, directed to the conscience of the hearer. A ministry of Christian teaching and preaching is a lifetime occupation because teaching cannot be discharged without preparation, and preparation requires time. For the Christian teacher to give himself to preparation, to the study of the word of God and its relevance, was never more needed than in the present generation.
-D. Broughton Knox, “What Must not change in a Changing Ministry”, Selected Works Vol II, pp 213-214.
This is such an important notion that it really is worth dwelling on. "If this ministry dies out then Christianity dies out." That's not rhetorical flourish from Broughton. It is simple statement of fact, arrived at by reflecting on the character of Scripture and by watching what happens in churches where this teaching ministry is lost, for one reason or another (but mainly because the teachers of the congregation stop being persuaded that it is important and manage to get themselves sidetracked).
Encourage your Bible teachers to keep doing it. Pray for them. If you are a Bible teacher, stick at it and let God be praised for the work you are doing. Don't let yourself get distracted! And if you are not a Bible teacher, but you understand how important the gospel is, then why not pray that God would lead you and gift you to be a teacher of his word; or that God will give you teachers that you yourself can be praying for and encouraging. If you are reading this late on a Sunday or early on a Monday, pray for your minister who at the moment is no doubt feeling a little tired and wondering if he is making any difference. (To the minister: Yes! You are making a difference! And thank you.)