Genesis 9:13, "I have set my rainbow in the clouds, and it will be the sign of the covenant between me and the earth."
Obviously, the rainbow is a symbol of God's promise that He will never destroy the earth by a flood again. But it is also a sign of God's grace and mercy to mankind. The story of the ark is a picture of God's provision for man's spiritual salvation. The ark of safety in the flood symbolizes Jesus Christ, who is our Ark of safety from the punishment for sin that we all deserve. Noah and his family had to enter the ark in order to be saved from the flood, and we have to enter into a covenant with Jesus, accepting Him as Savior, in order to be rescued from sin's power and eternal consequences.
Rainbows appear after rainstorms. God hasn't promised us that we won't have any storms in our lives, but the rainbow reminds us that our heavenly Father won't let the storms destroy us, nor will He leave us to face the storms alone.
Rainbows are formed when the sun and the water droplets align under just the right conditions. The colors of the rainbow reflect the sun's rays as they hit falling mist or watery spray. When we reflect God under difficult circumstances, people will see in us something even more special that a rainbow. Our lives will be a beautiful reflection of God's nature and faithfulness if we allow Him to shine through the storms in our lives.