The Bible message for a July 13th birthday is taken from Deuteronomy 7:13 and the verse reads..
"He will love you and bless you and make you into a great nation. He will give you many children and give fertility to your land and your animals. When you arrive in the land He swore to give your ancestors, you will have large crops of grain, grapes, and olives, and great herds of cattle, sheep, and goats."