Well since the Old Covenant isn't coming back and will never have a high priesthood in light of Christ's Perfect, Permanent High Priesthood, that's not going to happen.
Let's look at your Deuteronomy 6 passage, shall we?
10 When the Lord your God brings you into the land he swore to your fathers, to Abraham, Isaac and Jacob, to give you—a land with large, flourishing cities you did not build, 11 houses filled with all kinds of good things you did not provide, wells you did not dig, and vineyards and olive groves you did not plant—then when you eat and are satisfied, 12 be careful that you do not forget the Lord, who brought you out of Egypt, out of the land of slavery.
That first part is pointing to Grace - New Life apart from your own labor - rest in Christ. It's a type/shadow of the Reality we have in Christ in the New Covenant. The New Life we have in Christ is because of forgiveness we don't deserve and righteousness we didn't earn. Simply by entering in by faith we have New Life in Christ.
13 Fear the Lord your God, serve him only and take your oaths in his name. 14 Do not follow other gods, the gods of the peoples around you; 15 for the Lord your God, who is among you, is a jealous God and his anger will burn against you, and he will destroy you from the face of the land. 16 Do not put the Lord your God to the test as you did at Massah. 17 Be sure to keep the commands of the Lord your God and the stipulations and decrees he has given you. 18 Do what is right and good in the Lord’s sight, so that it may go well with you and you may go in and take over the good land the Lord promised on oath to your ancestors, 19 thrusting out all your enemies before you, as the Lord said.
20 In the future, when your son asks you,“What is the meaning of the stipulations, decrees and laws the Lord our God has commanded you?” 21 tell him: “We were slaves of Pharaoh in Egypt, but the Lord brought us out of Egypt with a mighty hand. 22 Before our eyes the Lord sent signs and wonders—great and terrible—on Egypt and Pharaoh and his whole household. 23 But he brought us out from there to bring us in and give us the land he promised on oath to our ancestors.
24 The Lord commanded us to obey all these decrees and to fear the Lord our God, so that we might always prosper and be kept alive,as is the case today. 25 And if we are careful to obey all this law before the Lord our God, as he has commanded us, that will be our righteousness.”
Now compare that to what actually happens to those under the Law - Law actually stirs up sinning, so it can never be our righteousness. Note that in the Old Covenant righteousness was dependent on obedience to the Law - it's earned; in the New Covenant, righteousness is dependent on belief in Christ and is a gift.
The Law was given to prove to man what God already knew: man cannot ever be righteous enough by not sinning. In fact, after the Cross, God clarifies this for us:
19 Now we know that whatever the law says, it says to those who are under the law, so that every mouth may be silenced and the whole world held accountable to God. 20 Therefore no one will be declared righteous in God’s sight by the works of the law; rather, through the law we become conscious of our sin.
21 But now apart from the law the righteousness of God has been made known, to which the Law and the Prophets testify. 22 This righteousness is given through faith in Jesus Christ to all who believe. There is no difference between Jew and Gentile, 23 for all have sinned and fall short of the glory of God, 24 and all are justified freely by his grace through the redemption that came by Christ Jesus. (from Rom. 3)
Jesus applies the comand for us to Love in Matthew 22, not the Law given at Sinai.
37 Jesus replied: “‘Love the Lord your God with all your heart and with all your soul and with all your mind.’ 38 This is the first and greatest commandment. 39 And the second is like it: ‘Love your neighbor as yourself.’ 40 All the Law and the Prophets hang on these two commandments.” (from Mt. 22)
And after the Cross, John defines just what the commandments of God are:
23 And this is his commandment, that we believe in the name of his Son Jesus Christ and love one another, just as he has commanded us. 24 Whoever keeps his commandments abides in God, and God in him. And by this we know that he abides in us, by the Spirit whom he has given us. (from 1 Jn. 3)
I'm opposing nothing. Simply rightly dividing the Word of Truth.
-JGIG