Obviously the Mosaic Law and Covenant are the same thing...no one is arguing the point. The point of contention is that in your statement above Paul clearly says that was the case! Galatians 3:1-5
You foolish Galatians, who has bewitched you, before whose eyes Jesus Christ was publicly portrayed as crucified?
2 This is the only thing I want to find out from you: did you receive the Spirit by the works of the Law, or by hearing with faith?
3 Are you so foolish? Having begun by the Spirit, are you now being perfected by the flesh?
4 Did you suffer so many things in vain—if indeed it was in vain?
5 So then, does He who provides you with the Spirit and works miracles among you, do it by the works of the Law, or by hearing with faith?
So already, in the above passage you see your above statement is wrong! That's exactly why Paul wrote Galatians. He says so clearly also in Galatians 6:11-13:
11 See with what large letters I am writing to you with my own hand.
12 Those who desire to make a good showing in the flesh try to compel you to be circumcised, simply so that they will not be persecuted for the cross of Christ.
13 For those who are circumcised do not even keep the Law themselves, but they desire to have you circumcised so that they may boast in your flesh.
Is that not Paul telling the Galatians saints they did not have to keep the Law???
Yet you CANNOT show anywhere where this is the case. Just as I have showed you even the OC was a matter of faith.
One more time I point to Paul saying why Israel failed...Romans 9:30-33:
30 What shall we say then? That Gentiles, who did not pursue righteousness, attained righteousness, even the righteousness which is by faith;
31 but Israel, pursuing a law of righteousness, did not arrive at that law.
32 Why? Because they did not pursue it by faith, but as though it were by works. They stumbled over the stumbling stone,
33 just as it is written, “Behold, I lay in Zion a stone of stumbling and a rock of offense, And he who believes in Him will not be disappointed.”
Until you grasp that even the Law was to be done in faith, you're going to keep the line of thinking you have. Paul clearly says Israel failed because THEY DID NOT PURSUE righteousness under the Law BY FAITH!!!
The OT is loaded with passages showing even the OC was to be done in faith. How could Habakkuk 2:4 say this in the OC?:
4 “Behold, as for the proud one, His soul is not right within him; But the righteous will live by his faith.
It's not a proof text at all when you hold the context, which you do not. What you do is REASON in your thinking of what the passage is saying.
Once again Romans 9:30-33:
30 What shall we say then? That Gentiles, who did not pursue righteousness, attained righteousness, even the righteousness which is by faith;
31 but Israel, pursuing a law of righteousness, did not arrive at that law.
32 Why? Because they did not pursue it by faith, but as though it were by works. They stumbled over the stumbling stone,
33 just as it is written, “Behold, I lay in Zion a stone of stumbling and a rock of offense, And he who believes in Him will not be disappointed.”
Once again also...you must then tear Hebrews 11 out of your bible as it list OT saints that had FAITH and did not pursue righteousness by the Law. Then again why does Paul quote Habakkuk 2:4 in Romans 1:16, 17???
The obvious point is that the OC Law was to be done in FAITH. If this is not the case How does Jesus say of Abraham in John 8:56
56 Your father Abraham rejoiced to see My day, and he saw it and was glad.”
Paul then...in Romans 4:1-8 totally refutes your thinking DECLARING Abraham had FAITH. For brevity I'll only quote the question...Romans 4:1, 2:
What then shall we say that Abraham, our forefather according to the flesh, has found?
2 For if Abraham was justified by works, he has something to boast about, but not before God
The case is then made that NO ONE is justified by works...so once again the Law was to be pursued by FAITH...and that is Israel's failure...and the error of your thinking.
Does Paul say the "penalty of the law" in either of those passages? NO! What he clearly says is..."Christ ABOLISHED in His flesh the enmity"...what was the enmity? Paul tells you what it was..."the LAW OF COMMANDMENTS contained IN ORDINANCES".
Where are those ordinances written New World? They start at Exodus 20 and end at Exodus 24...which is the Mosaic Law, Mosaic Covenant, the Law, the Old Covenant, the Sinaitic Covenant...whatever you want to call them! Paul declared them to be ABOLISHED at the cross! You can try to explain it away...but Paul said it was ABOLISHED!