I Tim. 3:14-16
Paul had plans to meet with Timothy soon, but he wrote this letter in order to give instructions before his arrival. If he were unable to visit Timothy until later, this letter would help him to better minister to the Ephesian church, the house of God.
The church is not a literal house of brick, wood or stone, but a spiritual house comprised of Christians. Paul described it as the pillar and ground (foundation and support) of the truth. It is to teach by word and example the truth (gospel) to the world.
Paul continued by explaining the mystery of godliness (truth of the Gospel). God was made known in the flesh as Jesus. He by the Holy Spirit performed miracles showing that God was with Him; as the Son of God endured the cross; was raised from the dead and carried back to heaven. Angels ministered to Him at various times and announced His resurrection. Jesus was preached to the Gentiles bringing them salvation as well as to the Jews. Even though not everyone believes in Him, Jesus has had a greater impact on the world than any other person. He is now on His throne at the right hand of God where He is Lord of lords and King of kings.