God is a Holy God. His Kingdom is undefiled. He calls his people to be Holy, separate from the world. The commands in Torah were for the sole purpose of teaching his people to remain clean and undefiled, so they may come before him in Worship.
Those defiled were removed from camp, unable to come near the Temple in worship, and required to follow Gods decrees to become clean again. Once the requirements of the Law were fulfilled, it was the Priest who examined and declared you clean.
All of these commands are a shadow pointing to the New Covenant Church and Gods Messiah, the High Priest who makes us clean.
Lev 11:46 "'These are the regulations concerning animals, birds, every living thing that moves in the water and every creature that moves about on the ground. 47 You must distinguish between the unclean and the clean, between living creatures that may be eaten and those that may not be eaten.'"
Lev 20:25 "'You must therefore make a distinction between clean and unclean animals and between unclean and clean birds. Do not defile yourselves by any animal or bird or anything that moves along the ground — those which I have set apart as unclean for you. 26 You are to be holy to me because I, the Lord, am holy, and I have set you apart from the nations to be my own.
Num 5:1 The Lord said to Moses, 2 "Command the Israelites to send away from the camp anyone who has an infectious skin disease or a discharge of any kind, or who is ceremonially unclean because of a dead body. 3 Send away male and female alike; send them outside the camp so they will not defile their camp, where I dwell among them."
Ezra 9:1 After these things had been done, the leaders came to me and said, "The people of Israel, including the priests and the Levites, have not kept themselves separate from the neighboring peoples with their detestable practices, like those of the Canaanites, Hittites, Perizzites, Jebusites, Ammonites, Moabites, Egyptians and Amorites. 2 They have taken some of their daughters as wives for themselves and their sons, and have mingled the holy race with the peoples around them. And the leaders and officials have led the way in this unfaithfulness."
The commands to be holy, and the regulations to become clean again for those who be became defiled in any way, played a big part of Gods people who could not live up to
Acts 15:8 God, who knows the heart, showed that he accepted them by giving the Holy Spirit to them, just as he did to us. 9 He made no distinction between us and them, for he purified their hearts by faith. 10 Now then, why do you try to test God by putting on the necks of the disciples a yoke that neither we nor our fathers have been able to bear? 11 No! We believe it is through the grace of our Lord Jesus that we are saved, just as they are."
The Messiah fulfills the requirements of the law and redeems mankind by his blood of the covenant.
Matt 11:28 "Come to me, all you who are weary and burdened, and I will give you rest. 29 Take my yoke upon you and learn from me, for I am gentle and humble in heart, and you will find rest for your souls. 30 For my yoke is easy and my burden is light."
James 1:27 Religion that God our Father accepts as pure and faultless is this: to look after orphans and widows in their distress and to keep oneself from being polluted by the world.
Matt 15:8 "'These people honor me with their lips, but their hearts are far from me.
9 They worship me in vain; their teachings are but rules taught by men.'"
10 Jesus called the crowd to him and said, "Listen and understand. 11 What goes into a man's mouth does not make him 'unclean,' but what comes out of his mouth, that is what makes him 'unclean.'"
…15 Peter said, "Explain the parable to us."
16 "Are you still so dull?" Jesus asked them. 17 "Don't you see that whatever enters the mouth goes into the stomach and then out of the body? 18 But the things that come out of the mouth come from the heart, and these make a man 'unclean.' 19 For out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false testimony, slander. 20 These are what make a man 'unclean'; but eating with unwashed hands does not make him 'unclean.'"
2 Cor 6:14 Do not be yoked together with unbelievers. For what do righteousness and wickedness have in common? Or what fellowship can light have with darkness? 15 What harmony is there between Christ and Belial? What does a believer have in common with an unbeliever? 16 What agreement is there between the temple of God and idols? For we are the temple of the living God. As God has said: "I will live with them and walk among them, and I will be their God, and they will be my people."
17 "Therefore come out from them and be separate, says the Lord.
Touch no unclean thing, and I will receive you."
18 "I will be a Father to you, and you will be my sons and daughters, says the Lord Almighty."
7:1 Since we have these promises, dear friends, let us purify ourselves from everything that contaminates body and spirit, perfecting holiness out of reverence for God.
Rom 10:4 Christ is the end of the law so that there may be righteousness for everyone who believes.
Col 2:13 When you were dead in your sins and in the uncircumcision of your sinful nature, God made you alive with Christ. He forgave us all our sins, 14 having canceled the written code, with its regulations, that was against us and that stood opposed to us; he took it away, nailing it to the cross. 15 And having disarmed the powers and authorities, he made a public spectacle of them, triumphing over them by the cross.
16 Therefore do not let anyone judge you by what you eat or drink, or with regard to a religious festival, a New Moon celebration or a Sabbath day. 17 These are a shadow of the things that were to come; the reality, however, is found in Christ.
1 John 1:7 If we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus, his Son, purifies us from all sin.
Heb 5:14 But solid food is for the mature, who by constant use have trained themselves to distinguish good from evil.
Heb 9:13 The blood of goats and bulls and the ashes of a heifer sprinkled on those who are ceremonially unclean sanctify them so that they are outwardly clean. 14 How much more, then, will the blood of Christ, who through the eternal Spirit offered himself unblemished to God, cleanse our consciences from acts that lead to death, so that we may serve the living God!
Heb 10:19 Therefore, brothers, since
we have confidence to enter the Most Holy Place by the blood of Jesus,
20 by a new and living way opened for us through the curtain, that is, his body, 21 and since we have a great priest over the house of God, 22 let us draw near to God with a sincere heart in full assurance of faith,
having our hearts sprinkled to cleanse us from a guilty conscience and having our bodies washed with pure water. 23 Let us hold unswervingly to the hope we profess, for he who promised is faithful.
Ps 24:3 Who may ascend the hill of the Lord? Who may stand in his holy place?
4 He who has clean hands and a pure heart, who does not lift up his soul to an idol or swear by what is false.
Matt 23:25 "Woe to you, teachers of the law and Pharisees, you hypocrites! You clean the outside of the cup and dish, but inside they are full of greed and self-indulgence. 26 Blind Pharisee! First clean the inside of the cup and dish, and then the outside also will be clean.
1 Cor 6:9 Do you not know that the wicked will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders 10 nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God. 11 And that is what some of you were. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God.