As husbands sacrifice their lives for the sake of their wives - loving, leading, serving, protecting, and providing for them – the world gets a glimpse of God's grace. Sinners see that Christ has gone to a cross where He suffered, bled, and died for them so that they could experience eternal salvation through submission to Him. They also see in a wife's relationship with her husband that such submission isn't a burden to bear. Marriage onlookers observe a wife joyfully and continually experiencing her husband's sacrificial love for her and then gladly and spontaneously submitting in selfless love to him. In this visible representation of the gospel, the world realizes that following Christ isn't a matter of forced duty. Instead, it's a means to full, eternal, and absolute delight.
David Platt