The Ekklesia of Christ Taught the Gospel
Jesus said, "...upon this rock I will build my church (ekklesia) and the gates of hell shall not prevail against it" (Matthew 16:18, emp LS). The ekklesia (church) of Christ: 1) met on the first day of every week (Sunday, Acts 20:7); 2) ate the Lord's supper on the first day of every week (Acts 20:7); 3) prayed together (Acts 2:42); 4) sang "psalms and hymns and spiritual songs" (Ephesians 5:19; Colossians 3:16); 5) and gave of their prosperity to the Lord every first day of the week (Acts 2:44-45; I Corinthians 16:1-2); 6) and also taught the Word of God.
Jesus gave His disciples a commission, "Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen" (Matthew 28:19-20, emp LS).
On the day of Pentecost, the apostles taught "the wonderful works of God" (Acts 2:11) concerning "Jesus the Nazarene" (Acts 2:22) saying, "Therefore let all the house of Israel know assuredly, that God hath made that same Jesus, whom ye have crucified, both Lord and Christ" (Acts 2:36). The apostle Peter taught, "Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost...And with many other words did he testify and exhort, saying, Save yourselves from this untoward generation. Then they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls. And they continued stedfastly in the apostles' doctrine and fellowship, and in breaking of bread, and in prayers" (Acts 2:38, 40-42).
From that day forward (“the beginning” Acts 11:15), "daily in the temple, and in every house, they ceased not to teach and preach Jesus Christ" (Acts 5:42). Stephen lost his life because he preached the truth of God's Word (Acts 7:58ff). "And Saul was consenting unto his death. And at that time there was a great persecution against the church which was at Jerusalem; and they were all scattered abroad throughout the regions of Judaea and Samaria, except the apostles...Therefore they that were scattered abroad went every where preaching the word" (Acts 8:1, 4 emp LS).
Paul taught that the ekklesia of Christ is, "the pillar and ground ("support", NASB) of the truth" (I Timothy 3:15). Therefore, the ekklesia of Christ used the Lord's money (collected on Sunday, I Cor. 16:1-2) to support preachers to preach and teach God's Word, "Even so hath the Lord ordained that they which preach the gospel should live of the gospel" (I Corinthians 9:14). Paul himself received money from the ekklesia of Christ so that he might preach the Gospel of Jesus Christ to others (Philippians 4:15-18).
The first century ekklesia taught the Gospel of Jesus Christ.