King David gives us insight into obtaining the "one thing" we desire - "Wait for the LORD; be strong, and let your heart take courage; yes, wait for the LORD" (Psalm 27:14).
By repeating the phrase "wait for the LORD," David emphasizes our need for perseverance in beholding the Lord. If we don't immediately see His face, we must continue waiting with the heart of Jacob - "I will not let you go unless you bless me" (Genesis 32:26). Shortly after prevailing with God, Jacob testifies to the reward of his perseverance - "I have seen God face to face" (Genesis 32:30).
"The LORD is good to those who wait for Him, to the person who seeks Him" (Lamentations 3:25) is His sure promise to you.