Galatians 3:24: “Therefore the Torah has become our tutor to lead us to Messiah, that we may be justified by faith.”
the fellow you mention, I don't know and won't go read what he says. there'd be no purpose to at this time, Yhwh be Pleased.
but you brought up a lot , opened up a proverbial 'can of worms', potentially, and there's only one way to go straight to the Truth, to learn the Truth, and to not be deceived. As it is written, no man can receive anything unless it is granted to him from above. i.e. if Yhwh doesn't allow, permit, and reveal the truth and open (even the disciples) the mind to see it, it is not seen nor grasped nor understood. 'Learning' from sunday school teachers, pastors, priests, scholars, Paul, Apollos, (apostles), or even from angels, if and when it is not as it is written and once for all delivered,
then it is not true. Test everything. Yhwh always delivers the Truth to His Children. But conversely, "all men are liars". That 'looks' like it is taken out of context, but it is surprisingly accurate. Everything, everyone must always be tested with much prayer and checking Scripture, asking Yhwh for His Word - in line with all that is written, not just part, and never contradictory to Himself.
One thing I do not comprehend here, in my life, at this point in time, is how anyone is able to learn the truth, let alone more than one at a time. The reason I don't comprehend it, is that everyone, practically speaking, holds on to some part of what they learned in the past, often for "good reason", yet that is exactly what prevents them from learning more. Just now, it occurred to me , perhaps this is Yhwh's Way, not to prevent anyone from learning the truth, but to reveal as He is Pleased to Reveal it, all in His Time.(and He knows Perfectly what is best for each person).
As I just posted in another thread, the same applies >>
Luke 10:21 (CJB) | In Context | Whole Chapter
21 At that moment he was filled with joy by the Ruach HaKodesh and said, “Father, Lord of heaven and earth, I thank you because you concealed these things from the sophisticated and educated, yet revealed them to ordinary people. Yes, Father, I thank you that it pleased you to do this.
Luke 10:21 (AMP) | In Context | Whole Chapter
21 In that same hour He rejoiced and gloried in the Holy Spirit and said, I thank You, Father, Lord of heaven and earth, that You have concealed these things [relating to salvation] from the wise and understanding and learned, and revealed them to babes (the childish, unskilled, and untaught). Yes, Father, for such was Your gracious will and choice and good pleasure.