To beget sons through the gospel means, ‘to cause others to become sons of God and consequently one’s sons in Christ through preaching the gospel’.
During apostle Paul’s missionary journeys, many people in different places he touched became sons of God and consequently his sons in Christ, through receiving the gospel that he preached (eg. 1Cor. 14:15; 15:1-2; Phil. 1:1,3,5-7; 1Thes. 1:4-6; 2:13).
This is a major mark being alive in Christ, or being a true child of God, in other words called “bearing fruit” (Jn. 15:16). No other form of Christian service can replace it, yet there are multitudes, who busy themselves out with other things to the exclusion of this all-important issue of begetting sons through the gospel.
Worse still, there are others who will not engage in anything at-all, who also claim to be Christians.