"When Moses went and told the people all the Lord’s words and laws, they responded with one voice, ‘Everything the Lord has said we will do.’ 4 Moses then wrote down everything the Lord had said.
He got up early the next morning and built an altar at the foot of the mountain and set up twelve stone pillars representing the twelve tribes of Israel. 5 Then he sent young Israelite men, and they offered burnt offerings and sacrificed young bulls as fellowship offerings to the Lord. 6 Moses took half of the blood and put it in bowls, and the other half he splashed against the altar. 7 Then he took the Book of the Covenant and read it to the people. They responded, ‘We will do everything the Lord has said; we will obey.’
8 Moses then took the blood, sprinkled it on the people and said, ‘This is the blood of the covenant that the Lord has made with you in accordance with all these words.’
9 Moses and Aaron, Nadab and Abihu, and the seventy elders of Israel went up 10 and saw the God of Israel. Under his feet was something like a pavement made of lapis lazuli, as bright blue as the sky. 11 But God did not raise his hand against these leaders of the Israelites; they saw God, and they ate and drank.
12 The Lord said to Moses, ‘Come up to me on the mountain and stay here, and I will give you the tablets of stone with the law and commandments I have written for their instruction.’
13 Then Moses set out with Joshua his assistant, and Moses went up on the mountain of God. 14 He said to the elders, ‘Wait here for us until we come back to you. Aaron and Hur are with you, and anyone involved in a dispute can go to them.’
15 When Moses went up on the mountain, the cloud covered it, 16 and the glory of the Lord settled on Mount Sinai. For six days the cloud covered the mountain, and on the seventh day the Lord called to Moses from within the cloud. 17 To the Israelites the glory of the Lord looked like a consuming fire on top of the mountain. 18 Then Moses entered the cloud as he went on up the mountain. And he stayed on the mountain forty days and forty nights" (Exodus 24:3-18).
Note verse 8.
"Moses then took the blood, sprinkled it on the people and said, ‘This is the blood of the covenant that the Lord has made with you in accordance with all these words.’"
The first covenant was inaugurated through the sprinkling of blood. Every time a priest sprinkled blood on the alter or near it, the people should have remembered the words they spoke to Moses in verse 7.
“Then he took the Book of the Covenant and read it to the people. They responded, ‘We will do everything the Lord has said; we will obey.’
They knew what would happen if they continued to live in disobedience (see Deut 11:10-27).
The New Covenant was also inaugurated through the spilling of blood. Jesus spilled his own blood to inaugurate the New Covenant and to establish himself as the High Priest for all time.
If we call ourselves his disciples, we have made a covenant with him. We have chosen to trust and obey him.
"So then, whoever eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of sinning against the body and blood of the Lord. 28 Everyone ought to examine themselves before they eat of the bread and drink from the cup. 29 For those who eat and drink without discerning the body of Christ eat and drink judgment on themselves" (1 Cor 11:27-29).
"Examine yourselves to see whether you are in the faith; test yourselves. Do you not realize that Christ Jesus is in you—unless, of course, you fail the test?" (2 Cor 13:5)
“Don’t you know that when you offer yourselves to someone as obedient slaves, you are slaves of the one you obey—whether you are slaves to sin, which leads to death, or to obedience, which leads to righteousness? 17 But thanks be to God that, though you used to be slaves to sin, you have come to obey from your heart the pattern of teaching that has now claimed your allegiance. 18 You have been set free from sin and have become slaves to righteousness” (Rom 6:16-18).
“Anyone who does not provide for their relatives, and especially for their own household, has denied the faith and is worse than an unbeliever” (1 Tim 5:8).
According to these vereses, the person who continues to disobey Jesus has denied him, even if they claim to believe in him. The disobedient deny Christ by their actions. Being "in the faith" means trusting and obeying Jesus. It does not mean accepting some theory about why Jesus died and rose from the dead.
Note carefully Paul's words in Romans 6:17 and 18.
“...you have come to obey from your heart the pattern of teaching that has now claimed your allegiance. 18 You have been set free from sin and have become slaves to righteousness.”
In the Old Testament the sprinkling of blood by the high priest, was to remind the people of the covenant they had made with God. It had a similar purpose to the eating of bread and drinking wine in remembrance of Jesus death on the cross.
When we don't trust and obey Jesus, we are denying him.
“Distrust is atheism and the barrier to all growth.” ~ George MacDonald
The way to be made right with God has always been the same. First, the relationship is established through trust. Those who believe God is good come to him on his terms; they accept the Messiah and swear to follow him.
“...without faith it is impossible to please God, because anyone who comes to him must believe that he exists and that he rewards those who earnestly seek him” (Heb 11:6).
The first act of obedience is to confess ones sin and swearing allegiance to the rightful king. The first act of obedience, if sincere, will be followed by a life of trust and obedience. God has always required trust and obedience.
Under the Old Covenant, the people were made right with God by obeying the laws Moses gave. (But since no one perfectly obeyed the law of Moses, repentance was central to restoring their relationship with God. There is not a single instance of forgiveness in the Bible without repentance. But there are many instances of forgiveness without a sacrifice having been made. God does not require perfection in the repentant; but he does require trust. See here. The sacrifices in the OT—which God graciously provided—were intended to bring about repentance in the person who was offering the sacrifice, or in the people whom the sacrifice was being offered for. Repentance is the necessary condition of forgiveness, not the spilling of blood. For an in-depth look at the purpose and meanings behind the Old Testament sacrifices see Atonement, Justice, and Peace: The Message of the Cross and the Mission of the Church by Darrin W. Snyder Belousek.)
Under the New Covenant, people are made right with God by accepting that Jesus died for them and swearing allegiance to the Messiah (which is made public through baptism), and then trusting and obeying him. The person who continues to trust and obey Jesus is showing that they accept him as the rightful king; and they are showing that they accept the terms of the New Covenant. Those who do not accept those terms are in rebellion against God. (And just like in Old Testament times, God regards those who trust him as righteous; even though they fail to obey him perfectly. See here.)
Whenever God punished Israel in the Old Testament his purpose was to bring them to their senses. His punishment was always redemptive.
If Jesus death and resurrection are not enough to cause you to trust and obey him, God will use different means to bring you to your senses. Without repentance, there is no forgiveness of sins.
Now this theology scares some people. But it only scares them because they don't understand why God punishes. Jesus did not come to set us free from the punishment of sin. He came to save us from sin itself. See here.
Without the shedding of blood, Hebrews 9:22