Saint Isaac the Syrian compares our life in this world to crossing the sea in a ship.
Just as it isn't possible for someone to cross the great sea without a ship, so someone can't reach love without fear. We can cross the tempestuous sea placed between us and the spiritual paradise only with the ship of repentance, borne by the oarsmen of fear. If these oarsmen of fear don't handle the ship of repentance well, by which we cross the sea of this world toward God, we will be drowned in it.
Repentance is the ship, fear is the rudder, love the divine harbor. So fear puts us in the ship of repentance and we cross the tempestuous sea and it guides us to the divine harbor, which is love where all those who labor and have been enlightened by repentance arrive. And when we have reached love, we have reached God. And our journey has ended and we have reached the island which is beyond this world.
Notice how he emphasizes that it is only with this "ship of repentance" that we can reach our goal. Repentance is essential to arrive at the "divine harbor." It is the fundamental way we move toward perfection and a virtuous life of love based on God's grace. It is because of our desire for God's love, and to love others that we repent.
Ref: Orthodox Spirituality, p 140
