"Let us live up to what we have already attained." What I hear in that statement is act on the truth you know.
I may not feel ready to do the next-right-thing that's in front of me. I may feel as though I lack the knowledge, skills, or sheer courage to put one foot in front of the other. I may not know the fullness of what to do to fix any given situation. But I typically know enough to start. I can act on the truth I know. I just usually don't.
It's easier to wait for God to lay it all out. Because then my paralysis is His fault, not mine.
When I feel overwhelmed by a situation or an aspect of myself I need to work on, the enormity of it all makes me shrug. "I just don't know where to start." Because I don't know how to do it all, I do nothing.
And I call it "waiting on God". Meanwhile, He's waiting on me.
Why should I expect God to show me the whole plan when I'm not being obedient to the small thing He's already shown me? Why should I expect Him to keep speaking when I haven't acted on what He's already said?
As small and inconsequential as it may be, I need to do the bit I know to do. Take that first step. And trust that His light will shine at the exact moment I need to know what to do next.
I love the encouragement and challenge that's wrapped in the charge to "press on," a mere two verses earlier. I've never read on, though, and continued the thought. It's as though the next part is telling me how to press on. By living up to what I've already attained.
Press on. By acting on the truth you know.