Wow...a lot here to unpack but suffice to say we are never able to get to God...through anything...
He came to us...and comes to us...the obedient ones who know His voice...we must prepare ourselves to receive Him...do as He pleases and commands we do...
You cannot have a relationship with God through keeping the Mosaic Law.
Mosiac law was not designed to get us to God...but to point out our continued need for Him
It didn't do that, however, or Israel would not have failed so significantly and repeatedly.
Deut. 29:29
"The secret things belong to the LORD our God, but the things revealed belong to us and to our sons forever, that we may observe all the words of this law
What that verse states is that secret things belong to God, BUT the things revealed to Israel is the Law. God said the Law was in their mouths and on their hearts.
John 5:
38nor does His word abide in you, because you do not believe the One He sent. 39You pore over the Scriptures because you presume that by them you possess eternal life. These are the very words that testify about Me
In other words, the Mosaic Law testified to, pointed to Christ. He is the Finisher of it. There is no need for it, because now He is here. You need to post that verse in context. Please note, it's about Jesus, not Moses.
John 5
31 If I bear witness of myself, my witness is not true. 32 There is another that beareth witness of me; and I know that the witness which he witnesseth of me is true. 33 Ye sent unto John, and he bare witness unto the truth. 34 But I receive not testimony from man: but these things I say, that ye might be saved. 35 He was a burning and a shining light: and ye were willing for a season to rejoice in his light. 36 But I have greater witness than that of John: for the works which the Father hath given me to finish, the same works that I do, bear witness of me, that the Father hath sent me. 37 And the Father himself, which hath sent me, hath borne witness of me. Ye have neither heard his voice at any time, nor seen his shape. 38 And ye have not his word abiding in you: for whom he hath sent, him ye believe not. 39
Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me. 40 And ye will not come to me, that ye might have life. 41
I receive not honour from men. 42 But I know you, that ye have not the love of God in you. 43
I am come in my Father’s name, and ye receive me not: if another shall come in his own name, him ye will receive. 44
How can ye believe, which receive honour one of another, and seek not the honour that cometh from God only? 45 Do not think that I will accuse you to the Father: there is one that accuseth you, even Moses, in whom ye trust. 46
For had ye believed Moses, ye would have believed me: for he wrote of me. 47 But if ye believe not his writings, how shall ye believe my words?
Luke 24:27
And beginning with Moses and all the Prophets, he explained to them what was said in all the Scriptures concerning himself.
Yes, that the OT was testifying of Him who had come. They pointed to Christ - He is the Way, the Truth, and the Life --- He who fulfilled all the Law and Prophets through His own blood on the cross, nailing the hand written ordinances that were against us to the tree. Jesus was not teaching the Mosaic Law to these men - He was preaching the Gospel to them, showing them the prophecies concerning Himself in the OT. The focus of the New Covenant is on Jesus Christ, not Moses and not on Israel, but one new man through the blood of Christ Jesus.