The season of distress and anguish before us will require a faith that can endure weariness, delay, and hunger,—a faith that will not faint, though severely tried. The period of probation is granted to all to prepare for that time. Jacob prevailed because he was persevering and determined. His victory is an evidence of the power of importunate prayer. All who will lay hold of God’s promises, as he did, and be as earnest and persevering as he was, will succeed as he succeeded. Those who are unwilling to deny self, to agonize before God, to pray long and earnestly for his blessing, will not obtain it. Wrestling with God—how few know what it is! How few have ever had their souls drawn out after God with intensity of desire until every power is on the stretch. When waves of despair which no language can express sweep over the suppliant, how few cling with unyielding faith to the promises of God.
– The Great Controversy, pg. 621