I get it and I think the answer is somewhere in between. People get a bit confused in this area, and I'll touch on one reason why:
People are constantly stopping others here when they say to be good or even mention the term "good" at all. They answer with none are truly good, which of course is a quote from Christ and is true, but Christ never said we couldn't be/do good, and as a matter of fact, to the contrary. He only was getting it straight that the term Good is something that no one is 100%/truely.
Yet here he says we must be good, so if we can't be good, why does Christ expect that in order for us to get to heaven, yet we know people will go to heaven? Because we can be good, at least as good as good gets.
John 5:28-29
“Do not be amazed at this, for a time is coming when all who are in their graves will hear his voice and come out—those who have done what is good will rise to live, and those who have done what is evil will rise to be condemned. By myself I can do nothing; I judge only as I hear, and my judgment is just, for I seek not to please myself but him who sent me.
And it's also true our righteousness is like dirty rags to God, or compared to God, but that doesn't mean we have no righteousness and I do not agree with the people that are constantly reminding those who try to do right, or say we should try to be good of being no more than a dirty rag or not really "good" at all.
As you say in the OP, there is a time for building up to. I think those things we are told in the Bible are just so we can get some perspective, but not designed to make us constantly look at the ground in shame/tell ourselves or others how awful we really are.
Sometimes people do good and people should simply recognize that, tell them so, stand behind them and give them reason to tread on by doing more good tomorrow, and leave the negative out. We don't have to worry that some will get a fat head, people that try to do good know better, and they also give God all the credit, while at the same time, we/they did do something, as in have the faith and take the initiative to obey God, something that I think should be recognized. Hey, we don't get much of a reward here in this age, can we at least not treat ourselves or others like they are nothing? As OP says, God thinks we're something, something pretty important.
Getting to heaven is one heck of an accomplishment, and I think we need to honor those who dare to join in on that battle/race.
And I do realize, there are many who do treat people and themselves pretty well/have a realistic view of things, but I just though this might go along with what the point the OP is putting across.
Good job. OP.