Matthew 23:23 “Woe to you, scribes and Pharisees, hypocrites! For you tithe mint and dill and cumin, and have neglected the weightier matters of the law: justice and mercy and faithfulness. These you ought to have done, without neglecting the others.”
Men can dedicate their whole lives to God but still find it difficult to be right.
Numbers 11:16-17 English Standard Version
16 Then the Lord said to Moses, “Gather for me seventy men of the elders of Israel, whom you know to be the elders of the people and officers over them, and bring them to the tent of meeting, and let them take their stand there with you. 17 And I will come down and talk with you there. And I will take some of the Spirit that is on you and put it on them, and they shall bear the burden of the people with you, so that you may not bear it yourself alone.
This was the foundational principle for the Sanhedrin.
Numbers 11:24-25 English Standard Version
24 So Moses went out and told the people the words of the Lord. And he gathered seventy men of the elders of the people and placed them around the tent. 25 Then the Lord came down in the cloud and spoke to him, and took some of the Spirit that was on him and put it on the seventy elders. And as soon as the Spirit rested on them, they prophesied. But they did not continue doing it.
What did they stop? Obviously the Sanhedrin of Jesus’ time did not have the Spirit resting upon them. Let us continue to see what had happened.
Numbers 11:26-29 English Standard Version
26 Now two men remained in the camp, one named Eldad, and the other named Medad, and the Spirit rested on them. They were among those registered, but they had not gone out to the tent, and so they prophesied in the camp. 27 And a young man ran and told Moses, “Eldad and Medad are prophesying in the camp.” 28 And Joshua the son of Nun, the assistant of Moses from his youth, said, “My lord Moses, stop them.” 29 But Moses said to him, “Are you jealous for my sake? Would that all the Lord’s people were prophets, that the Lord would put his Spirit on them!”
And here we are today, thanks be unto our Lord Jesus Christ, fulfilling Moses’ word.
Historically it appears the tradition that began with Moses choosing the 70 was heavily influenced by the conqueror Alexander the Great and the practices of the Greek Senate.
Perhaps that is where things went wrong.