The Commandments

After travelling for three months, the Israelites had arrived at Mount Sinai. There, they would set up a covenant with God who had liberated them from the bondage in Egypt. Previously, God made covenants with individuals: Noah (Genesis 9:9), Abraham (Genesis 15:18), Isaac (Genesis 17:21) and Jacob (Genesis 28:13-15). These previous covenants were mostly promises which God pledged to honour. Men did nothing on their part. Simply put, God had no rights and men had no obligation. Men were enjoying a pure favour from God.

Now God was making a covenant with a people. Here, men began to fulfil certain obligations. Yet, it was still an unfair treaty because the two parties involved, God and the Israelites, were not on equal footing. In ancient time, when a strong nation entered into a covenant with a weak one, it was more a granting of favours on the part of the stronger one to demonstrate her wealth and splendour. The weaker one repaid only with a symbolic gesture of honour instead of real substance. A weaker nation would eagerly seek such a covenant to buy herself safety. A strong nation could afford to enter one such covenant to show off her might among aspiring empire builders. With these background ideas, let's take a look at this Sinai Covenant.
You have seen what I did to the Egyptians, and how I bore you on eagles' wings and brought you to myself.
Now therefore, if you will obey my voice and keep my covenant, you shall be my own possession among all peoples; for all the earth is mine,
and you shall be to me a kingdom of priests and a holy nation (Exodus 19:4-6a).
God began with a recount of how He delivered the Israelites from the bondage in Egypt. This was a typical opening of a treaty between a strong overlord with his vassal. It clearly demonstrated the Israelites' dependence on God. Then came the obligations of the vassal --- to obey His voice and keep His covenant. This is obvious. But what about the benefits, the rights? Among all peoples, Israel belongs to God. If God be a king, this benefit will amount to being chosen by the king to enter the palace. Of course, God is more than a king. If it is not clear enough, God elaborated. The Israelites would be a kingdom of priests and a holy nation.
In ancient time, priests enjoyed the highest status in the society because they were the middle-men between heavens and men. Just imagine. Gather all the priests all over the world and form a nation. That is Israel. Each Israelite is a priest on behalf of a clan, a tribe, a people or a nation. Peter must have this idea in mind when he wrote to the Christians in Pontus, Galatia, Cappadocia, Asia, and Bithynia.
But you are a chosen race, a royal priesthood, a holy nation, God's own people, that you may declare the wonderful deeds of him who called you out of darkness into his marvelous light (1 Peter 2:9).

As a sign of a covenant, rainbow and circumcision had been used. These are more likely to be etymology stories than authentic covenants. However, the Sinai Covenant is more developed. Rights and obligations were stipulated. They were more clearly spelt out. Now, we have the Ten Commandments (Exodus 20:1-17). What is Jesus' attitude towards them?
When the rich young man asked Jesus how to inherit eternal life, Jesus gave the following preliminary answer.
You know the commandments: 'Do not kill, Do not commit adultery, Do not steal, Do not bear false witness, Do not defraud, Honor your father and mother.' (Mark 10:19)
Jesus affirmed that keeping the commandments was the first step to attain eternal life. If you do not lead an ethical life, how can you lead an eternal one? However, Jesus gave only six, not ten. What about the remaining commandments? What about the confessing of one, true God? the honouring of the name of God and the observance of Sabbath?
From the mouth of Jesus, we hear the Christian affirmation of the Jewish ethics. On the other hand, as far as the relationship with God is concerned, Christians and Jews stand on different grounds. Take the observance of Sabbath as an example. Circumcision and keeping the Sabbath had been characteristics of the Jewish identity. However, as more and more Gentiles became Christians, celebrating the resurrection of Christ on Sunday would be more meaningful than celebrating God's rest on Sabbath. The Jerusalem Council further declared that circumcision was unnecessary for salvation (Acts 15). Christians were trying to cut themselves off from the Jews.
As for the oneness of God, Gentile Christians had less burden than Jewish Christians in confessing that Jesus was God. For this reason, Saul persecuted the early Christians. This also probably explains why Jesus was silent about the first few commandments. He remained ambiguous to allow people to interpret it either way --- Christians have taken them for granted or Christians are still struggling with the divinity of Jesus. Indeed, Christology had occupied the best minds for the next couple of centuries.

Dear Lord, You have shown us the way. Let us keep Your commandments to lead a sanctifying life. We adore You, the Blessed Triune God. Amen.