I don't think Paul ever disagrees with God, it is you that erroneously thinks Paul, called to be an apostle by Jesus Christ and the will of God, is in disagreement with God.
I do not think that Paul was in disagreement with God, which is why I don't interpret him as saying things that are in disagreement with what God has said. God's law can't both be not too difficult to obey and impossible to obey, so you are interpreting Paul as contradicting God.
So many false presumptions. . .
Therein you err Biblically, because Scripture does not contradict itself. . .to follow Paul is to follow Christ and God, by whose will Paul was made an apostle (1 Corinthians 1:1; 2 Corinthians 1:1; Galatians 1:1; Ephesians 1:1; Colossians 1:1, etc.)
I agree that following Paul is following Christ and God, which is why you are wrong to interpret Paul in way that makes him out to be speaking against following Christ and God.
Contrare. . .read it again. . .it couldn't be more clear.
Galatians 3:10 - All who rely on observing the law are under a curse. (Galatians 3:10)
What part of that do you not understand?
Romans 3:20 - Therefore, no one will be declared righteous in God's sight by observing the law; rather, through the law we become conscious of sin.
I can cite where Paul spoke about a law that is not of faith (Galatians 3:10-12) and a law that our faith upholds (Romans 3:31), so in order to correctly understand Paul, we need to recognize that he spoke about multiple categories of law other than the Law of God. For example, in Romans 3:27, he contrasted a law of works with the law of faith, so works of the law are a law of works, while our faith upholds the Law of God, so it is of faith, and he directly contrasted works of the law with the Law of God. Likewise, in Romans 7:25, Paul contrasted the Law of God with the law of sin.
God is trustworthy, therefore His law is also trustworthy (Psalms 19:7), and a law that isn't trustworthy can't come from a God who isn't trustworthy, so to rely on God's law is to rely on God, while to deny that we should rely on God's law is to deny that we should rely on God. However, in Galatians 3:10-12, the problem was that they were relying on works of the law instead of relying on the Book of the Law and thus they were coming under the curse for not relying on the Book of the Law. Paul associated a quote from Habakkuk 2:4 with a quote from Leviticus 18:5, so the righteous who are living by faith are the same as those who are living in obedience to the Book of the Law, while no one who relies on works of the law will be justified because they are not of faith in God, unlike the Book of the Law. In Isaiah 51:7, the righteous are those on whose heart is God's law, so the righteous living by faith does not refer to a manner of living that is not in obedience to it.
In Romans 3:21-22, the Law and the Prophets testify that the righteousness of God comes through faith in Christ, so this has always been the one and only way that there has ever been to become righteous, which the Law and the Prophets testify about, so the law was never given for the purpose of providing a means of becoming righteous, but that does not mean that we shouldn't rely on it for the purposes for which it was given.
Not to mention it likewise being irrelevant to the point of discussion: being able to obey the law according to God's requirements, where the NT reality of Jesus Christ is:
1) the law was not given to make righteous, that having already been given by faith only since Abraham (Genesis 15:6, Romans 4:3),
2) the law was given only to reveal sin (Romans 3:20, Romans 7:7),
3) no one will be declared righteous in God's sight by observing the law (Romans 3:20)
4) Psalms 14:1-3, 53:1-30), all have sinned and fall short of the glory of God (Romans 3:23)for all are under sin (Romans 3:9), there is no one righteous, not even one (Romans 3:10;
I can't figure out why you keep stating that the law was not given to make us righteous while I keep agreeing with you and have never stated otherwise. If you agree that the law was given to reveal sin and that we should refrain from doing what God has revealed to be sin, then you should agree that we should obey it.
The reality is that you conveniently overlook the fact of Joshua 22:1-3 referring to Joshua's commands to the Gadites and Reubenites regarding taking possession of Canaan (Numbers 32:25, 29; Joshua 1:16, 18) and is not referring to the Mosaic law.
Matthew 22:2 and said to them, “You have kept all that Moses the servant of the Lord commanded you and have obeyed my voice in all that I have commanded you.
That verse is most definitely referring to the Mosaic Law.
That's good to know, but it sure looks like that to me in your above statement; i.e.,
the reality is that Galatians 3:10 says nothing about it being impossible for man to obey God's law in order to avoid its curse.
As you keep stating, God's law was never given to make us righteous, so regardless of the issue of whether or not we can obey the law, we can't become righteous by obeying it either way. Even if someone managed to live in perfect obedience to God's law, then they still wouldn't earn their righteousness by it because God's law was not given to make us righteous. That was never the reason for why we should obey it.
Then why do you keep presenting a false conflict between Paul and God, as you do at the top of this post?
God said we can obey it and you say that it is impossible to obey, which is in conflict with God, so I am not the one presenting them as being in conflict.
Keeping in mind what that law of God in the NT is. . .the law of Jesus in Matthew 22:37-40, which fulfills the whole law (Romans 13:8-10), and in the New Covenant is written on our hearts of flesh, not on tablets of stone or on parchment.
In the NT, we are not under the law of Moses (1 Corinthians 9:20), we are under the law of Christ, which is the law of God (1 Corinthians 9:21).
If we love God and our neighbor, then we won't commit adultery, theft, murder, idolatry, rape, kidnapping, and so forth for all of the other laws that God has given, so the greatest two commandments are inclusive of all of the other commandments, which is why Jesus said in Matthew 22:36-40 that those are the greatest two commandments and that all of the other laws hang on them. In 1 Corinthians 9:21, Paul said in a parallels statement that we are not outside the Law of God, but under the Law of Christ, so he equated the Law of God with the Law of Christ, and the Law of Moses is referred to as the Law of God in both the OT and the NT (Nehemiah 8:1-8, Ezra 7:6-12m Luke 2:22-23). Christ called for people to repent for the Kingdom of God is at hand and the Law of Moses is how they knew what sin is, and Christ set a sinless example of how to walk in obedience to the Law of Moses, so he spent his ministry teaching how to obey it both by word and by example, and it wouldn't make sense for you to think that the Law of Christ was something other than what Christ spent his ministry teaching.