“The Greek word musterion (“mystery”), when used in the New Testament, refers to the things of God that were once hidden but were later revealed through Christ and the coming of the Holy Spirit (Acts 2:4). A mystery is that which can only be known through the revelation of God (Romans 16:25–26; Colossians 1:26–27). It is something that in times past had been hidden but is now revealed to God’s people.”

“…The apostle Paul used the word mystery 21 times in his epistles: the mystery of God(Colossians 2:2), the mystery of faith(1 Timothy 3:9), the mystery of iniquity(2 Thessalonians 2:7), etc. In each case, the “mystery” involved a declaration of spiritual truth, revealed by God through divine inspiration. The New English Translation of 1 Timothy 3:16 speaks of the mystery of godliness as an “amazing revelation” concerning our faith…”(Source: GotQuestions.com – article “What is the mystery of godliness?”)

The “mystery of godliness” is, in essence, Jesus, because He, in His life, death, and resurrection, is the way to God and to godly living. 

“Beyond all question, the mystery from which true godliness springs is great: He (Jesus) appeared in the flesh, was vindicated by the Spirit, was seen by angels, was preached among the nations, was believed on in the world, was taken up in glory.”

‭‭1 Timothy‬ ‭3‬:‭16‬ ‭NIV‬‬

“As He walked this earth, Jesus was the embodiment of pure godliness, which led Him to lay down His life for unworthy sinners (John 10:18). His life was dedicated to the glory of the Father, and He always did what pleased Him (John 8:29). Christians pursue godliness when we follow the example of Jesus in dedicating every decision to the glory of God (1 Corinthians 10:31). Godliness is not a suggestion; it is a command (1 Peter 1:15–16; Hebrews 12:14).”

(GotQuestions.com)

Jesus’ entire life, from conception to resurrection, had one purpose…to restore sinful humans to fellowship with God. 

God’s “mystery” was hidden in the Old Testament, the promise given, in a prophecy, first, via the serpent in Eden…

“And I will put enmity between you and the woman, and between your offspring and hers; he will crush your head, and you will strike his heel.”

‭‭Genesis‬ ‭3‬:‭15‬ ‭NIV‬‬

…then building momentum through the history of God’s people…culminating in Isaiah’s prophecies…

“For to us a child is born, to us a son is given, and the government will be on his shoulders. And he will be called Wonderful Counselor, Mighty God, Everlasting Father, Prince of Peace. Of the greatness of his government and peace there will be no end. He will reign on David’s throne and over his kingdom, establishing and upholding it with justice and righteousness from that time on and forever. The zeal of the Lord Almighty will accomplish this.”

‭‭Isaiah‬ ‭9‬:‭6‬-‭7‬ ‭NIV‬‬

…and, finally, fully revealed in God’s Son. 

“But when the set time had fully come, God sent his Son, born of a woman, born under the law, to redeem those under the law, that we might receive adoption to sonship.”

‭‭Galatians‬ ‭4‬:‭4‬-‭5‬ ‭NIV‬‬

However, God’s revelation didn’t stop there. It had a conclusion in His plan, not only for the Jews but for all nations…through Abraham. 

“I will make you into a great nation, and I will bless you; I will make your name great, and you will be a blessing. I will bless those who bless you, and whoever curses you I will curse; and all peoples on earth will be blessed through you.”

‭‭Genesis‬ ‭12‬:‭2‬-‭3‬ ‭NIV‬‬

“He redeemed us in order that the blessing given to Abraham might come to the Gentiles through Christ Jesus, so that by faith we might receive the promise of the Spirit.”

‭‭Galatians‬ ‭3‬:‭14‬ ‭NIV‬‬

Much as the Jews in Paul’s day hated the Gentiles, even persecuting Paul because of his mission to the  non-Jewish world…

“Then the Lord said to me, ‘Go; I will send you far away to the Gentiles.’ ” The crowd listened to Paul until he said this. Then they raised their voices and shouted, “Rid the earth of him! He’s not fit to live!”

‭‭Acts‬ ‭22‬:‭21‬-‭22‬ ‭NIV‬‬

…Paul concluded that God’s mystery was only fully revealed  when the Gentiles also came into the kingdom and had a share in the blessings promised to Abraham. 

“Surely you have heard about the administration of God’s grace that was given to me for you, This mystery is that through the gospel the Gentiles are heirs together with Israel, members together of one body, and sharers together in the promise in Christ Jesus.”

‭‭Ephesians‬ ‭3‬:‭2‬, ‭6‬ ‭NIV‬‬

God’s “mystery” was not something unfathomable and unknowable…but a truth concealed until the right moment for it to be revealed. He had planned, from before the foundation of the earth, before the first ray of light shone in the darkness, to redeem His fallen human family. 

God’s daring plan centred in His own Son. He, the human Jeshua, would become one of us. He would live among us and die for us to pay our unpayble debt. The redemption price He paid would include every living thing, all humanity and creation itself…everything ruined by sin. 

“For the creation waits in eager expectation for the children of God to be revealed. For the creation was subjected to frustration, not by its own choice, but by the will of the one who subjected it, in hope that the creation itself will be liberated from its bondage to decay and brought into the freedom and glory of the children of God.”

‭‭Romans‬ ‭8‬:‭19‬-‭21‬ ‭NIV‬‬

Jesus did all this for one all-inclusive purpose…godliness!

“Godliness in the Bible means a lifestyle of deep reverence, devotion, and practical obedience to God.” (Google AI)

“By his divine power, God has given us everything we need for living a godly life. We have received all of this by coming to know him, the one who called us to himself by means of his marvelous glory and excellence. And because of his glory and excellence, he has given us great and precious promises. These are the promises that enable you to share his divine nature and escape the world’s corruption caused by human desires.”

‭‭2 Peter‬ ‭1‬:‭3‬-‭4‬ ‭NLT‬‬

Outside of Jesus, godliness is impossible. What He did…

“Beyond all question, the mystery from which true godliness springs is great: He appeared in the flesh, was vindicated by the Spirit, was seen by angels, was preached among the nations, was believed on in the world, was taken up in glory.”

‭‭1 Timothy‬ ‭3‬:‭16‬ ‭NIV‬‬

…made the impossible possible. Through Him, now, heaven is populated, and the whole earth is peppered with godly people, made holy through His blood.