What are the arguments for the existence of God?

* The design argument --- Design points to a designer
* The cause and effect argument --- The universe had a beginning therefore it must have a cause. 
* The moral argument --- We, humans, have a sense of right and wrong. If we are merely physical, where did we get this sense of right and wrong?
* The resurrection of Christ 
* Fulfilled prophecies
* The existence of the paranormal dimension 

Explain Galatians 4:1-2

Ga 4:1 Now I say that the heir, as long as he is a child, does not differ at all from a slave, though he is master of all, 2 but is under guardians and stewards until the time appointed by the father.

The Israelites under the Law of Moses were viewed and treated as a child while the saints in the New Testament are viewed and treated as an adult son. 

Just as you need to repeat yourself when instructing a child so you will find repetitions in the Old Testament. Just as you need to instruct a child in great detail so you read detailed instructions in the Old Testament. Just as you need to use object lessons with a child so the saints in the Old Testament had many object lessons in the form of ceremonies, feasts and all. Just as you expect little from a child so did God expect less from them. In fact, God predicted their failure. 

It's very different with treating an adult son. You don't have to repeat yourself in great detail. You don't have to say much but you expect a great deal from him. Moreover, you don't need a lot of object lessons. 

Around 5 or 6 years old, a Roman child had a tutor.  The job of the tutor was to protect the child and instill the family values into him. That was the Law. However, by the time he turns 16 or 17, he would no longer need a tutor. At this point, he would undergo a procedure called adoption. 

Adoption in Roman culture is not the same as we have it today. "Adoption" in their culture means son-placing. It refers to the child of a father who has come of age. He is now legally recognized as the son who will be the heir of the father with all its privileges and responsibilities.