King James Version
But let him ask in faith, nothing wavering. For he that wavereth is like a wave of the sea driven with the wind and tossed.English Standard Version
But let him ask in faith, with no doubting, for the one who doubts is like a wave of the sea that is driven and tossed by the wind.New International Version
But when he asks, he must believe and not doubt, because he who doubts is like a wave of the sea, blown and tossed by the wind.