The Lord calls us to go the whole way with Him, to walk with Him. Enoch walked with God, and in fact walked so close to Him, went so far with Him that the Bible implies he didn’t have to go through death, God simply took him away (Gen 5:24).
But then there’s a lot of instances however of people called by God to walk with Him, but who only went halfway through. Terah was probably one such person; he set out from Ur of the Chaldeans to make his way to Canaan, the destination that Abraham would eventually reach, but he only made it as far as Haran. The Bible seems to imply that God had in fact called Terah to make the journey his son would eventually make, but the father of the patriarch did not walk with God all the way. He settled for Haran and stayed there, unable to attain the inheritance and surrounded by pagans till his death. (Gen 11:31)
In the same way Lot stopped short of walking with God. He must have known where his uncle Abram was headed, and heard from Abram himself the promises God made and the inheritance awaiting them in Canaan. But Lot saw that the plain of Jordan was good, saw with his eyes, and settled for less-than-Promise. (Gen 13:10-11) He never attained the inheritance that he surely would have shared in, had he stuck to Abram.
The Reubenites and Gadites saw with their eyes that something less than the Promise was good. The lands of Jazer and Gilead were suitable for their livestock. (Num 32:1) So they refused to go the whole way to Canaan. They, along with the half-tribe of Manasseh completely disowned their inheritance beyond the Jordan, disowned their share of God’s Promise (Num 32:19). And when the LORD stirred up the spirit of Tiglath-Pileser king of Assyria, the people of these tribes fell alone beyond the Jordan, with no one to help them. And though they were not the first to fall to Assyria, the Bible credits their fall alone to their unfaithfulness and prostitution to other gods. (1 Chron 5:25-26) They did not walk the whole way with God, and fell apart from Him.
To some extent Barak’s story is like this. He was called by God (or rather by Deborah on God’s behalf) to fight the Canaanite lord Jabin and his general Sisera. Now it’s easy to point the finger at Barak’s refusal and call him a coward – Lord knows I’ve shrunk back and shirked when God called me forward – but we can see that shrinking back, not going with God the whole way, really is a shame. Barak refused to go the whole way: “If you go with me,” he told Deborah, “I will go; but if you don’t go with me, I won’t go.” (Jdg 4:6-8) And the response from God? Barak wasn’t struck down then and there, but he had to live with the fact that he didn’t go with God, didn’t attain the promise, in this case of victory. He had to live with the fact that the honour would not be his, for the LORD handed Sisera over to a woman. And Barak will forever be remembered as a man who shirked in the face of God’s calling and had a woman force him to fight.
A bit laborious in making this point, but it’s a simple one I have been taught: when God calls, you follow. The Lord may not strike you dead for not going the whole way, but the inheritance, the Promise, all these things will be forfeit. There will be no honour for those who stay across the Jordan. And when evil comes it’s all too easy to fall apart from God.
One last observation: Deut 6:24-25 has an Israelite tell his son:
“The LORD commanded us to obey all these decrees and to fear the LORD our God, so that we might always prosper and be kept alive, as is the case today. And if we are careful to obey all this law before the LORD our God, as he has commanded us, that will be our righteousness.”
And yet “Abram believed the LORD, and he credited it to him as righteousness.” (Gen 15:6)
Seems a bit incongruous, but – I’m just guessing here, Lord please correct me if I’m wrong – there seems to be a different way to look at ‘righteousness’ pre-Salvation and post-Salvation.
When Abram believed the LORD in Gen 15:6, this was in a way pre-Salvation, he hadn’t reached the Promise yet. But the Israelite in Deut 6:24-25 would have already been living in the Promise, would have been post-Salvation. Abram believed that God would save him while he was still unsaved, and that alone made him righteous. The Israelite, having already been saved, approached ‘righteousness’ in a sense that he was already righteous, already saved and in the Promise, and it needed working out. (Phil 2:12). After all, as James writes to Christians (note, not non-Christians!), isn’t faith proved genuine by works? Grace and faith alone allows us to attain righteousness while we are still unrighteous, but having attained it maybe righteousness takes on a different meaning – more in the way of sanctification? And that is something that must be worked out, laws are kept by saved people and that is their righteousness. I’m still not clear on this, and I pray the Lord will make this clear to me.
Remember, My Lord 
The Bible mentions two kind of righteousness, the righteousness by law and the righteousness from God (Rom 4 & 10). The former comes through work and the latter comes through faith in Jesus to all who believe. Those who seek to be justified by observing the law will find themselves always under the wrath of God, like those you mentioned in your writing on the unsettling parts of the Scripture. Paul has made this very clear in Romans 3:20, ‘No one will be declared righteous in his sight by observing the law; rather, through the law we become conscious of sin.’
However, you are right that although we can’t be justified by work, all Christians should bear good fruits as we are good trees. Those we are children of God will not lead a sinful life.