Does the Law's role in preparing for the Messiah apply to Gentiles?

Les explains that Paul uses the term “adoption” for the Law as a schoolmaster. In the illustration, a servant was hired and instructed to bring the child to the place where he could step in and work with the father. That is what the Law was intended to do for Israel: to prepare them and bring them to the place where, when the Messiah would come, they were ready. In faith they could have said yes, and a few did, but for the most part the nation rejected it. They could have believed everything that Christ was had they been ready, but they were not. Then it comes over into the Gentile economy, and it still is a valid concept that the Law was given to prepare everything for the coming of the Messiah, that He could fulfill the work of the Cross. He had to die, be buried, and be raised from the dead for our justification.