Seven is called the perfect number. It is the number of days in the week. Can you say all the days? Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, and Sunday. This is called a week. When you have gone through all seven days, you start over again.
Do you have special things you do on certain days of the week? On Sunday, we go to church. What do you do on the other days of the week?
God used the number seven a lot in the Bible. In one book of the Bible, Revelation, God talks about seven seals and seven trumpets, and seven promises, and seven churches. I think He likes the number seven.
The number seven is the one God uses as a perfect number. He is perfect and he uses the number seven for perfect things in the Bible, or things that are finished and complete. When you are coloring a picture and you are all through with it and ready to give it to your parents, it is complete and you have done your perfect work. God is perfect and does perfect work and seven is the number He uses many times to show us this.