The great lesson is that we should watch and the reason we should watch is that we do not know when he is coming and yet if we are not ready at that moment, he will take us by surprise. All who are taken by surprise will be shut out of heaven forever as the parable has shown. If we knew the time when Christ was to return, we could relax our watching and be off guard until that moment arrived. Because we do not know the time we must be always on our guard. God has deliberately hidden the precise time of Christ’s return so that we have to be constantly spiritually awake. This helps us not only in preparing for the last day but in facing every day of our lives in this world. The same vigilance that equips us to meet the Lord, also equips us to face temptation and to face our enemy the devil, for the way in which we watch is not to be constantly studying the signs, but to keep our hearts from sin. That is the very best of preparation and will mean that we are fully prepared even though we have never studied eschatology and are unfamiliar with the signs. The signs are given to us to encourage us in keeping our hearts.