You've heard the phrase "Don't just stand there, do something"? So oft repeated is this idiomatic expression that there's even a Christianized version of it. The kind of thing you'd see on a church marquee: "Don't just do something, stand there". What do I do? What do I do?
The latter phrase in question is referring to the potential dichotomy of action versus inaction with reference to seeking after and following God's will. And I would like to say that the phrase God helps those who help themselves is nowhere to be found in the Bible. It should read God helps the helpless who know they're helpless and want His help.
What does the Bible say about such things? Well, first of all, someone who wants to know God's will for their life is already headed in the right direction. That desire doesn't come from anywhere but Him.
"Thou rulest the raging of the sea: when the waves thereof arise, Thou stillest them." (Psalm 89:9)
Any activity--or inactivity for that matter--that arises out of torment, worry or pressure is more than likely going to lead you away from the path on which God wants you. And it will end up being just that: mere activity. This, I think would be one of the main reasons that God calls us to wait upon Him. The devil is notorious at pressuring people to act in accordance with some fear, real or imagined. If there is uncertainty regarding any decision, large or small, that you have to make, you gotta know that there is spiritual warfare going on regarding the outcome. Moses told the Israelites to "fear not, stand still, and see the salvation of the Lord, which He will shew to you to day" (Exodus 14:13 emphasis mine). The next verse says "The Lord shall fight for you".
"But they that wait upon the Lord shall renew their strength; they shall mount up with wings as eagles; they shall run, and not be weary; and they shall walk, and not faint." (Isaiah 40:31)
This verse has its own dichotomy. Or so it would seem. While the first part says to wait, the second part talks about walking and running. Alright! Now we're getting somewhere. But what about the fear and indecision? May I suggest 1 John 4:18? "There is no fear in love; but perfect love casts out fear: because fear has torment. He (or she) that fears is not made perfect in love." God is a stickler for pure motives. I would venture to say, that if we don't realize, fully realize the strong fact that God loves us and are able to grasp hold of this reality, then we probably shouldn't do anything. Because anything we do is not based on the most stable reality of existence: God loves me. Matthew 9, verse 23: "All things are possible to [them] that believe" this fact.
This is why Paul could say that he "pressed toward the mark for the prize of the high calling of God in Christ Jesus (Philippians 3:14). The next verse reads "Let us therefore, as many as be perfect, be thus minded". Paul had been made "perfect in love", as it says in the previous paragraph. God can do something with the man, the woman who knows God loves them. This is spiritual perfection.
Now, moving forward, consider this statement of Paul's: "All things are lawful (possible) unto me, but all things are not expedient" (1 Corinthians 6:12) What I think he's saying here is, while he may feel this extraordinary liberty to go and do whatever he thought he should because he knew the love of God, he tempered that liberty by realizing that not all activity will lead to what God wanted to do in his life with reference to the world at large. This is another reason for waiting. When you know that God loves you, you're more sensitive to His will and consequently, you don't want to displease Him by doing your own thing. Even though you know that God loves you in spite of any disobedience.
This truly is the happy medium. When one realizes that God loves them, they end up walking in the will of God naturally, easily. "The steps of a good man (or woman) are ordered by the Lord: and He delighteth in [their] way." (Psalm 37:23) And then, I suppose that this would be the answer to both statements. Don't just stand there do something! Don't just do something, stand there! How 'bout we not do anything (standing, sitting, running, jumping, waiting, whatever, etc.), anything at all, until we realize that God loves us?
In closing, a quick caveat: "As free, and not using your liberty for a cloak of maliciousness, but as the servants of God." (1 Peter 2:16)