Jeremiah 35: it is possible to obey a human being. Why is it so difficult to obey the Lord?

 In Jeremiah 35, the Lord uses the Rechabites’ community as an example of obedience. They were not supposed to drink wine. Would they still not be drinking wine?

3-4 So I (Jeremiah, I suppose) went and got Jaazaniah son of Jeremiah (instead of "my son"?), son of Habazziniah, along with all his brothers and sons—the whole community of the Recabites as it turned out—and brought them to God’s Temple and to the meeting room of Hanan son of Igdaliah, a man of God. It was next to the meeting room of the Temple officials and just over the apartment of Maaseiah son of Shallum, who was in charge of Temple affairs.

5 Then I set out chalices and pitchers of wine for the Recabites and said, “A toast! Drink up!”

6-7 But they wouldn’t do it. “We don’t drink wine,” they said. “Our ancestor Jonadab son of Recab commanded us, ‘You are not to drink wine, you or your children, ever. Neither shall you build houses or settle down, planting fields and gardens and vineyards. Don’t own property. Live in tents as nomads so that you will live well and prosper in a wandering life.’

They didn´t drink wine in obedience to Jonadab (who lived in Jehu's time). The Lord didn´t ask to his whole people not to drink wine; but this community embraced it as commandment. Did the Lord approve it? Yes:

12-15 Then Jeremiah received this Message from God: “God-of-the-Angel-Armies, the God of Israel, wants you to go tell the people of Judah and the citizens of Jerusalem that I say, ‘Why won’t you learn your lesson and do what I tell you?’ God’s Decree. ‘The commands of Jonadab son of Recab to his sons have been carried out to the letter. He told them not to drink wine, and they haven’t touched a drop to this very day. They honored and obeyed their ancestor’s command. But look at you! I have gone to a lot of trouble to get your attention, and you’ve ignored me. I sent prophet after prophet to you, all of them my servants, to tell you from early morning to late at night to change your life, make a clean break with your evil past and do what is right, to not take up with every Tom, Dick, and Harry of a god that comes down the pike, but settle down and be faithful in this country I gave your ancestors.

The Lord is almost jeleous that this commnity obeyed their ancestor's command while his people don't obey Him. It is a big contrast: if humans can obey another human, why this difficult to obey the Lord?

In face of this:

17 “So here’s what is going to happen. God-of-the-Angel-Armies, the God of Israel, says, ‘I will bring calamity down on the heads of the people of Judah and Jerusalem—the very calamity I warned you was coming—because you turned a deaf ear when I spoke, turned your backs when I called.’”

but the Lord will honor that community:

18-19 Then, turning to the Recabite community, Jeremiah said, “And this is what God-of-the-Angel-Armies, the God of Israel, says to you: ‘Because you have done what Jonadab your ancestor told you, obeyed his commands and followed through on his instructions, receive this Message from God-of-the-Angel-Armies, the God of Israel: There will always be a descendant of Jonadab son of Recab at my service! Always!’”