Acts 1:1, “In the first book, O Theophilus, I have dealt with all that Jesus began to do and teach.”  

There’s a lot packed into those four words, “to do and teach.” In my estimation, “to do and teach” encompasses the entire book of Luke. These four words feel as if they are about to burst at the seams with all the history contained within. The entirety of Christ’s life, death, and resurrection, and all of His teaching are right there in those four little words “to do and teach.” 

Based on Luke’s statement in Acts 1:1, we must mean two things when we say “Yes, I’m a Christian.”

First, we must mean we follow His teaching. One can think they are devoted to God, yet be worshipping devils. Without the doctrine found in the Word of God, all that we have to guide us is our heart. And we know the heart is not our guiding light, for it is easily led astray and is deceitfully wicked (Jeremiah 17:9). God’s word is a lamp to our feet, and a light on our path. Through it, we see through the deceitful desires the world entices our hearts to yearn after, since it tethers our heart to the knowledge of the truth in the face of the lies of the world.

Then, we must mean we follow His actions. Doctrine matters, so does devotion. Our doctrine states we love Christ. And if we love Christ, then we will follow His commandments (John 14:15), which entails picking up our cross and following Him (Luke 9:23).

John Calvin wrote on the importance of following Christ’s words and deeds in his commentary over Acts: 

“Truth it is, that the manners of a good and godly teacher ought so to be framed, that he speak first with his life, then with his tongue, otherwise he should differ nothing from a stage-player. … For the office of the Messias did not only consist in doctrine, but it was also behoveful that he should make peace between God and man, that he should be a Redeemer of the people, a restorer of the kingdom, and an author of everlasting felicity.”

Christ not only gave the great Sermon on the Mount, but He also performed the greatest act of love at Golgotha (John 15:13). Paul commanded Titus and Timothy to teach sound doctrine (Titus 2:1, 1 Timothy 1:3); he also commanded those who preach live lives consistent with their calling (1 Timothy 3:1-13). And God Himself commands us to be holy, as He is holy (1 Peter 1:16). 

God sent Christ to die and rise again to save us from our sins. Thankfully, God not only tells us in his word to follow what he did and taught, he also saved us by his grace (Ephesians 2:8-9), gave us new hearts to long for him (Hebrews 8:10), and gave us his Spirit to dwell in and among us (John 14:23).

God guaranteed those whom he called would perform good deeds, not because of their own righteousness, but because Christ works on our behalf to glorify God, who in turn glorifies the Son and the Spirit (Ephesians 2:10, John 14:12-14). 

Luke mentioned that these were what Christ “began to do and teach.” Began implies continuation. All Scripture is God-breathed (2 Timothy 3:16), so when we read Paul, Peter, James, and John, we are indeed reading the teachings of Christ. Thus, the whole Bible from beginning to end, and everywhere in-between is the entire Word of God.  

Those four words call to remembrance not only Christ’s doctrine, his discourse with the disciples, and his parables to the Pharisees, but also of what Christ did during his time on earth: his life, death, and resurrection. “I have dealt with all that Jesus began to do and teach.” That, in essence, is the Gospel, and it’s what we’re commanded to follow. As Christians we witnes to what Christ did and taught while on Earth.

Our mandate as Christians is to believe on Christ, follow his commands, and teach others to do the same. It’s as simple as those four words, “to do and teach” from Luke.