God rewarded Simeon with this immense blessing of being told that the time was about to come. He was nearing the end of his life probably, but he would not die until he has seen this wonderful sight.
How it fills the saints with strength when they see that God does not fail them. They rightly look forward to the next blessing, being assured by the previous blessing, so that there is an unbroken chain of favours from God. This enables them to pass through this world of darkness without fear, without growing weary in well-doing, walking as optimists through the hopelessness of this life.