Predictably, the Apostle Paul focuses on the gospel of Jesus Christ in his final letter before his death (2 Timothy) . He knows that his time left on earth is short, “the time has come for my departure” (2 Tim 4:6), so Paul wants to impart to Timothy the importance of the gospel, what it is, and therefore why Christians should guard it. And in fact even more than guard it, disciples are called to even suffer for the gospel. Paul insists,
do not be ashamed of the testimony about our Lord or of me his prisoner. Rather, join with me in suffering for the gospel, by the power of God. (2 Tim 1:8)
Paul was at the time of writing languishing in a prison from which he would not leave except for his own execution. And yet he did not eschew his suffering but called others to join him. Let us consider why any rational person would suffer for something or seek to guard it at great personal cost?
What you heard from me, keep as the pattern of sound teaching, with faith and love in Christ Jesus. Guard the good deposit that was entrusted to you—guard it with the help of the Holy Spirit who lives in us. (2 Tim 1:13-14)
Paul reminds us of the critical importance of the gospel and therefore how and why we must seek to guard it.