NET
18 With every prayer and petition, pray at all times in the Spirit, and to this end be alert, with all perseverance and petitions for all the saints.
Darby
18 praying at all seasons, with all prayer and supplication in [the] Spirit, and watching unto this very thing with all perseverance and supplication for all the saints;
KJV
18 Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints;