"At the end of chapter 3 Paul impressed upon Timothy the sufficiency of Scripture for his ministry (3:16–17) so that, unlike the false teachers mentioned earlier in the letter, Timothy will stick with Scripture as the all-sufficient basis of his ministry, for the long run. Then follows the charge of 4:1–2, which spells out the precise way in which Timothy is to use this sufficient Scripture.
The charge is made up of five verbs in the imperative (‘preach the word’, ‘be ready in season and out of season’, ‘reprove’, ‘rebuke’ and ‘exhort’) followed by a prepositional phrase that qualifies them (‘with complete patience and teaching’). ... If the leading imperative ‘preach’ (kēryxon) is qualified by the four imperatives and the prepositional phrase that follow, each of these then communicates something of the nature of the preaching that Timothy is to engage in. To obey the charge to preach will require Timothy to be ready (epistēthi) ‘in season and out of season’,6 not least because sound teaching will not always be welcome (4:3). In his preaching, Timothy will have to ‘reprove’ (elenxon; that is, correct false understanding or sinful behaviour), ‘rebuke’ (epitimēson; that is, call his addressees to turn from ungodliness) and ‘exhort’ (parakaleson; that is, call the people to believe and live out the truth he proclaims). He is to do all this with ‘patience’ (makrothymia), because it will take time and perseverance for his addressees to accept and respond to God’s word. And he is to preach with ‘teaching’ (didachē), because his reprovals, rebukes and exhortations will only carry weight and be effective if they are grounded in a clear articulation and explanation of what the word of God says. Preaching the word cannot be reduced to teaching it (in the sense of simply explaining the meaning of the word as a purely didactic activity); it involves the urgent call to respond that is signified by the imperatives ‘reprove, rebuke and exhort’. At the same time, preaching for Timothy will always fundamentally involve teaching and can never happen apart from teaching."
Griffiths, Jonathan I. Preaching in the New Testament: An Exegetical and Biblical-Theological Study. Edited by D. A. Carson. Vol. 42. New Studies in Biblical Theology. England; Downers Grove, IL: InterVarsity Press; Apollos, 2017, 55-56.