Titus 1:9

holding to the faithful word which is according to the teaching, that he may be able both to exhort in the sound doctrine, and to convict the gainsayers.

As DeWelt noted, "This has been taken by many to be a commentary on 1 Timothy 3:2, in which Paul states that the elder must be `apt to teach'";[21] and that view would appear to be correct. The primary duty of elders, namely, that of watching over and protecting the flock of God, requires that they be students of the holy Scriptures, having a broad knowledge of what is and what is not sound doctrine.

That he may be able to convict the gainsayers ... This shows why an elder must be apt to teach and must possess an accurate and extensive knowledge of the holy truth revealed in the Scriptures. A moment later, Paul will give further information regarding the particular gainsayers he had in view here; but, apart from that, there are evil and seductive teachers in all generations who exercise their subversive talents for private gain, doing much damage to the faith of many. Such men must be prevented from achieving their evil purpose; and an eldership not having sufficient ability in the Scriptures is unequal to such a task.