William Burkitt on Romans 15:4

The apostle here informs us what is the general use of the holy scriptures, and what is the particular reason for which they were written; namely, 1. For instruction, they were written for our learning; all the precepts, promises, threatening, rewards and punishments, recorded in the scriptures, are for our information, conviction, and direction.

2. They were written for our comfort and consolation also, that we through patience and comfort of them might have hope; that is, that we through patience in bearing the like censures and reproaches, which we find the scripture-saints have borne before us, might have hope of being rewarded as they were for it.

Learn hence, That the great end for which the holy scriptures were written, was the informing of our judgments, and the directing of our practice; that by the examples which we find there of the patience of holy men under sufferings, and of God's relieving and comforting them in their distresses, we might have hope, yea, confidence and assurance, that God will also comfort and relieve us, under the like pressures and burdens.