Robert Murray M'Cheyne emphasizes the true pleasantness of being a child of God, contrasting the fleeting and false pleasures of the unconverted with the enduring joy found in Christ. He illustrates how, despite Christ's sorrows, He maintained a holy joy, and similarly, believers can experience profound joy amidst their struggles. M'Cheyne argues that true happiness comes from forgiveness, sanctification, and the eternal nature of God's promises, encouraging believers to live joyfully and to recognize the folly of seeking pleasure apart from Christ. He warns the unconverted of the temporary nature of their joys and the impending judgment they face without Christ.