"My heart leaps up when I behold a rainbow in the sky" is the first line of a poem of the same name by William Wordsworth. By its beauty alone the rainbow brings joy to the world. The rainbow is a sign that the rain has passed and that the sun is about to shine and this is a further reason for joy. It is a sign of hope for better hours to come. For those who believe in a loving God the rainbow is an even further cause of joy, the sign of an even greater hope.
The sign of the rainbow assured Noah on God's word of honour that never again would such a catastrophe as the massive flood occur. The evil power of sin, symbolized by the flood would never again come close to submerging God's plan of salvation. Indeed the very waters of the flood bore up the ark which was God's way of saving Noah and his family.
In our turn we are saved by the waters of baptism. It was after his baptism that Jesus went out to the desert to mount his first assault on the power of evil. United with Jesus in baptism we will have a share in defeating the power of evil. We need to be changed, to be converted before we can "come on board" for the struggle alongside Christ. By our baptism that process has already started.
Be with us, Lord, in the struggle You began in the desert so near to Your place of baptism.