From Slave to Son: Galatians 4:1-7

What I am saying is that as long as an heir is underage, he is no different from a slave, although he owns the whole estate. The heir is subject to guardians and trustees until the time set by his father.

Marcus was born into the household as a slave.

His mother had been a slave. He knew no other life. He swept the floors of the villa, carried water from the well, slept in the servants' quarters. The master's son, about his same age, ate at the table while Marcus waited on him.

So also, when we were underage, we were in slavery under the elemental spiritual forces of the world.