Eph 3:1-3, 1 For this reason I, Paul, a prisoner of Christ Jesus on behalf of you Gentiles 2 assuming that you have heard of the stewardship of God’s grace that was given to me for you, 3 how the mystery was made known to me by revelation, as I have written briefly.
The mystery of the Gospel is marvelously displayed in the book of Acts. In Acts 13:44-48, Paul preached the gospel to eagerly waiting Gentiles. Act 13:48 “And when the Gentiles heard this, they began rejoicing and glorifying the word of the Lord, and as many as were appointed to eternal life believed.” Large numbers believed and experienced salvation in Christ. God gave them power to believe as if to say they believed whose hearts the Lord opened (Act 16:14). God made them alive and gave them faith to believe.
The Spirit of God does move upon the human heart to which some respond, as here, but we cannot fully explain it. Jesus to Nicodemus, “The wind blows where it wishes, and you hear the sound of it, but cannot tell where it comes from and where it goes. So is everyone who is born of the Spirit.” (Joh 3:8).
It is explained but still our finite minds cannot comprehend it. Even the hymn writer was puzzled by the mystery of the gospel. “l know not how this saving faith to me He did impart, Nor how believing in His Word wrought peace within my heart. I know not how the Spirit moves, Convincing men of sin, Revealing Jesus through the Word, Creating faith in Him. But “I know Whom I have believed, And am persuaded that He is able to keep that which I’ve committed Unto Him against that day.””
Psa 37:39, “But the salvation of the righteous is from the LORD”