Romans 12:12 — Rejoicing in hope; patient in tribulation; continuing instant in prayer.
Hope — Hebrews 6:19 — Which hope we have as an anchor of the soul, both sure and stedfast, and which entereth into that within the veil.
Hope = faith in the future
instant in prayer — immediate
Nowhere does Paul instruct us to pray for long periods of time.
Perseverance in prayer produces joy in hope and patience in tribulation. Communion with God is essential as a controlling influence in our joy and in our patience under trial. Otherwise joy may be mere ebullition of feeling and patience mere Stoicism. — W.E. Vine, The Epistle to the Romans, page 181.