Paul uses an analogy that is similar to Galatians 3:23-25, where he likens the Old Covenant to a tutor meant to teach, but his application is very different. He says, "Now I say," indicating a different approach to his instruction.
As long as an heir is a child, as long as he is immature and unable to inherit, he is not much different from a servant. The child's potential is much greater, and his future is much brighter, but in day-to-day activities, he is restricted, limited, and controlled just as much as a servant of no lineage. The net effect of the immaturity is the absence of control. The child, like the servant, can only respond to what happens to him rather than having any power over his well-being or destiny.
Galatians 4:2 shows that the immature child is ruled over by others until the father, the one who gives the inheritance, decides that the heir can be freed from the grasp of the tutors and governors. This does not mean that at the "appointed time" the heir actually inherits from the father, but rather that at the appointed time he is no longer under the control of somebody else.
In this analogy, Paul does not say that the "tutors" and "governors" are positive elements, or that they are good for the child. He only says that they restrict the child and make him little better than a servant. Verse 3 likens the "tutelage" and "governance" to bondage, not like the schoolmaster of Galatians 3:24-25, which was meant to train and prepare.
In this series of verses, Paul is showing that until God the Father decides to drag someone out of this world (John 6:44), even though it has been preordained that they have a chance to "be a lord" and to inherit eternal life and other promises from the Father, they are powerless against the "elements of the world"—the rudiments of the cosmos, the world apart from God. These elements are demonic in nature. Before God called the Gentile Galatians, they were in bondage to sin and to Satan. Even though they had a higher potential—to inherit the Kingdom of God at the resurrection—until the appointed time when God saw fit to remove the shackles, they were just as controlled and powerless as the average servant of Satan.
Therefore, if you died with Christ from the basic principles [rudiments, KJV] of the world, why, as though living in the world, do you subject yourselves to regulations—"Do not touch, do not taste, do not handle," which all concern things which perish with the using—according to the commandments and doctrines of men?
Paul is clearly not referring to a commandment of God, as verse Colossians 2:22 shows. He is referring to false, pagan teachings that are considered to be the "basic principles" or "rudiments" of the cosmos.
This is also shown in Ephesians 2:1-3:
And you hath he quickened, who were dead in trespasses and sins; wherein in time past ye walked according to the course of this world, according to the prince of the power of the air, the spirit that now worketh in the children of disobedience: Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others.
Before God redeems a man and "quickens" him—makes him alive—he walks according to the course of the cosmos. This passage shows clearly that the cosmos is ruled by the "prince of the power of the air," Satan the Devil. His spirit works in the children of disobedience, and they serve him. They are powerless in his grasp until God pays for them with the blood of His Son.
The "elements of the world" in Galatians 4:3 cannot be a reference to the Mosaic law, because the Gentile Galatians were never exposed to it until after their conversion—after God had ordained that they be taken out of the control of the "governors of this world" (Ephesians 6:12). The "elements of the world" are those basic things that make this cosmos what it is—a world apart from God. These elements are sinful, rebellious, and pagan.
It is blasphemous to say that anything that God ordained as a way to live (e.g., the Old Covenant) would put a man in bondage, when God's every intent is to free mankind from the bondage of Satan, sin, and human nature (Exodus 6:6; 20:2; Deuteronomy 5:6; 13:5,10; John 8:33-36; Romans 8:15). Would God liberate the Israelites from the bondage of Egypt (Exodus 1:14; 2:23; 6:5; Deuteronomy 6:12; 8:14; 26:6; Acts 7:6-7) only to shackle them again? On the contrary, He had their best interests in mind, providing for them a "schoolmaster"—the Old Covenant—which would be in effect until the Messiah came. Those who declare that the law of God brings one into bondage are pronouncing that they are anti-Christ: "Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be" (Romans 8:7).
God's law is not a burden. It is a definition of right and wrong and an extension of God's own character. It is the way that He lives, and there is no Being in the universe that has more freedom than God! James refers to the law of God as the "perfect law of liberty" (James 1:25), not the "law of bondage." He also calls it the "royal law" (James 2:8), not the "weak and beggarly law." Further, the apostle John was inspired to write in I John 5:3 that "this is the love of God, that we keep His commandments: and His commandments are not grievous [burdensome]." It is the height of carnality and blasphemy to consider God's perfect, royal law of liberty to be a weak and beggarly element that keeps mankind in bondage.
Some have tried to use Galatians 4:3-5, 9-11 to argue that God's law in general, and the Sabbath in particular, has been "done away with." They twist these scriptures to try to say that God's law kept us in bondage, but now Jesus Christ has redeemed us from the law so we no longer need to keep the Sabbath(s) holy. This is ironic, because one of the fundamental meanings and symbols of the Sabbath is redemption and liberation—not from any moral law, but from slavery and bondage to Egypt (sin):
Keep the Sabbath day to sanctify it, as the LORD thy God hath commanded thee. Six days thou shalt labour, and do all thy work ... And remember that thou [were] a servant in the land of Egypt, and that the LORD thy God brought thee out [redeemed, rescued, freed] thence through a mighty hand and by a stretched out arm: therefore the LORD thy God commanded thee to keep the Sabbath day (Deuteronomy 5:12-13,15).
God had to instruct the Israelites about the Sabbath again because they had been in Egypt for centuries and had forgotten the instructions to their fathers. The Sabbath was reintroduced right after they were brought out of Egypt (Exodus 16), long before God made a covenant with Israel (Exodus 20). So, while the Sabbath command was a requirement included in the Old Covenant, its validity, importance, and necessity by no means ended when the Old Covenant became obsolete.