In Acts 11 we see three types of subject matter that need to be communicated by God’s servants.
11:20 preaching euaggelízō to announce good news, “evangelize”. This is to unbelievers. They really just need to hear the gospel. Until they grasp that nothing else really matters very much.
11:23 encouraging parakaléō to call alongside, exhort, admonish Related to parakletos, a title used of both Jesus and the Holy Spirit. (See John 14:16, 15:26, 16:7 and 1 John 2:1) This is especially to new believers. They need to go beyond the gospel itself and hear about commitment to Christ, growth and perseverance – so that they don’t see trials and fall away. More mature believers also still need this from time to time because, let’s face it, we get discouraged and need motivation.
11:26 teaching didáskō (like “didactic”) to impart instruction, explain or expound a thing, instill doctrine. This is educating Christians about God and the Christian life, communicating all that God has revealed to us – from A to Z, Alpha to Omega, the whole Bible from Genesis to Revelation, the Contents to the Maps. Teaching nourishes and matures a church. It is sorely needed in the church today. Many Christians are ignorant of the Scriptures and are therefore weak in their faith (Romans 10:17). We their pastors need to feed it to them.