How do we walk in fellowship without law?

By faith! Faith is sufficient.

Can we have full fellowship with the Lord independent of any unobeyed command out of scripture?

Yes! Abraham was called righteous independent (and beforehand) of his obedience to (outer-man) circumcision, even though he was obedient in the flesh, later.

"Under what circumstances was it credited? Was it after he was circumcised, or before? It was not after, but before!" rom 4:10

Here is a very important passage which describes how to consider righteousness in the eyes of God:

“Circumcision has value if you observe the law, but if you break the law, you have become as though you had not been circumcised. If those who are not circumcised keep the law's requirements, will they not be regarded as though they were circumcised? The one who is not circumcised physically and yet obeys the law will condemn you who, even though you have the written code and circumcision, are a lawbreaker.

A man is not a Jew if he is only one outwardly, nor is circumcision merely outward and physical. No, a man is a Jew if he is one inwardly; and circumcision is circumcision of the heart, by the Spirit, not by the written code. Such a man's praise is not from men, but from God.” rom 2:25-29

Verse 26 says that though a man is not obedient to any one law, because he has faith (i.e., he "keeps the law"), he is considered, he is seen through a lens as if he actually had been obedient to the law. How can this be so?

If we obey the greatest commandment, then there is nothing left in the law as undone. “...for he who loves his fellowman has fulfilled the law.” rom 13:8 What is the greatest commandment? To love God in perfection and to love men in perfection. No man has loved God and men by this standard, except One man. Jesus obeyed the greatest commandment to perfection. When He did this He not only gained the credit for it for Himself but also credited us with that same accomplishment. So because of the transfer of credit at our salvation, we are seen unmovingly as obedient in perfection to every single commandment. We are also made over into that real-life image of perfection (works) because of salvation.

Not only does the greatest commandment illustrate that it was more than just the laws of sacrifice that were satisfied by Jesus, but also the fact that the ‘law of Moses’ which is a usual name for the old covenant, includes not just the sacrifical laws but also the ten commandments. Jesus fulfilled all obligation to satisfy all law.

"Yet he did not waver through unbelief regarding the promise of God, but was strengthened in his faith and gave glory to God, being fully persuaded that God had power to do what he had promised. This is why 'it was credited to him as righteousness.' The words "it was credited to him" were written not for him alone, but also for us, to whom God will credit righteousness..." rom 4:20-24

Abraham's faith enacted righteousness. Completion of obedience in the work later on was not part of the enactment. Now, James talks about "works-righteousness." He seems to say to many ears that "there is a justification that comes by works." But, I still don't think I buy this. I think that the same connectedness that made Abraham seen as obedient as if by law, but really only and just by faith, is just as connected thinking reversely: His faith is made complete in what he did.

"A man is not a Jew if he is only one outwardly, nor is circumcision merely outward and physical. No, a man is a Jew if he is one inwardly...." rom 2:28-29

The outward only, means nothing. Abraham's example of obedience when he was said to be "making his faith complete," was not absent of faith. The faith was always present in the completion of the works of righteousness, in his obedience to God. So: if faith was there, and works were there, which one really brings justification? The faith brings the credit, in the work. The work itself does not, but, the faith is made full, complete, when it is built-up and taken outwardly through not only what is inward but into everything we do outwardly. Faith is qualitative, and quantitative. Faith is always the conduit of righteousness. Works, themselves, aren't adding anything toward being righteous... they aren't adding anything, but they represent the faith-righteousness that is beneath them.

Verse 25 sums up, in my thinking, the way to know if what I do means anything to God:

"For circumcision is indeed profitable if you keep the law; but if you are a breaker of the law, your circumcision has become uncircumcision. " rom 2:25

See how faith is indomitable, here, in determining standing before God? So, yes, a man is blameless before God when he has faith and yet is still giving the appearance, in the reality of any matter, as being a sinner. I love how clearly He portrays grace in Jesus Christ even in the OT:

“The poor will see and be glad--you who seek God, may your hearts live! The Lord hears the needy and does not despise His captive people.” ps 69:32-33

“The Lord is near to all who call on Him, to all who call on Him in truth. He fulfills the desires of those who fear Him; he hears their cries and saves them.” Ps 145:18-19

There is only one law which determines our sanctificational state of being in fellowship with God: the law of faith. The Law of Spirit and Life Rom 8:2. The Law of Christ gal 6:2. Prospering with Christ and His deposited Life, is measured by how much we receive as believable the truth of Christ crucified, for when we love we are in harmony with God and dispensing our responsiibility to make disciples of all men and also obeying the commands we carry consciousness of.

When He comes again we will not be judged another time for sins; no, we will be judged according to the depth of our faith (because God sees the true value of a work), not sins of the outer man (the ten commandments). john 16:8-9

“Speak and act as those who are going to be judged by the law that gives freedom.” james 2:12