Closely related to this idea is the concept that God answers specifically prayers of guidence with a feeling of peace regarding decisions.
Regarding both of those beliefs, I'm not entirely convinced that they are supported by Scripture. Of course, since I'm taking a "negative" posture, it is entirely possible that there are passages in Scripture that do support these views, and I just cannot remember them.
Still, a small voice?
Regarding the first idea of "waiting for the Lord" in silence. There are two passages that come to mind. First is the "small, still, voice" with Elijah in 1 Kings 19:12, and second is the "Wait for the Lord!" cry in Psalms.
As a side note, I'm not saying that we shouldn't "quiet our hearts" though I do think we should do this not by trying to empty our minds, but rather by meditating upon the attributes of God. But that's another post. (Is the phrase "quiet our hearts" in Scripture?)
Regarding the small, still voice (KJV translation), it seems to me that God is not saying, "Oh come out and pray for a bit, and I'll speak to you." God is already speaking to Elijah as can be seen by the context and is using what is outside as a demonstration of His power and His workings. Check out this post by centuri0n which was very informative. So we can acknowledge that there really isn't any support for the idea of "waiting for God" in prayer here at least.
The other passages that come to mind are those referring to "Be still and wait for the Lord!" in the Psalms. A quick search on Biblegateway for the phrase gives us this search. The context of all these texts are times of persecution, suffering, pain. It's certainly not prayer. It's a command for times of distress. "Don't avenge yourself. But be still and wait for the Lord!"
Psalm 37 is particularly clear on this point (but the rest of the Psalms have similar contexts) so I'll quote it for you:
7Be still before the LORD and wait patiently for him;
fret not yourself over the one who prospers in his way,
over the man who carries out evil devices!
8Refrain from anger, and forsake wrath!
Fret not yourself; it tends only to evil.
9For the evildoers shall be cut off,
but those who wait for the LORD shall inherit the land.
10In just a little while, the wicked will be no more;
though you look carefully at his place, he will not be there.
11But the meek shall inherit the land
and delight themselves in abundant peace.
Be still! Do not fret yourself when the wicked are propserous. Be still! Don't think to take God's justice in your own hands. Continue to pursue righteousness! It's definitely not, "be still and wait for me when you pray, because I will speak to you." Laying aside questions about the sufficiency of Scripture (which, in my mind, discourages such prayer), I don't think there is an encouragement for such prayer in the Bible.
God gave me "peace."
I'm not saying that God isn't also a God of peace. That He, as one of His gifts, does not give a supernatural peace in times of trial to His people upon occasion.
I'm not saying that the Christian life shouldn't be marked by peace and contentment in all things, plenty or in want.
I am saying that I don't think Scripture teaches that we should seek a specific feeling of "peace" regarding a specific decision as a confirmation that the decision is indeed "God's will."
6do not be anxious about anything, but in everything by prayer and supplication with thanksgiving let your requests be made known to God. 7And the peace of God, which surpasses all understanding, will guard your hearts and your minds in Christ Jesus.Do not be anxious about anything. Instead, with everything, pray with thanksgiving to God. When you do this, the peace of God will guard your hearts and your minds in Christ Jesus.
It's not "when you aren't anxious about something, then you know it's God's will for you." Instead it's "don't be anxious! Pray!" When you do pray, God's peace will guard you. Thus, instead of hoping for some supernatural feeling of "peace" to guide our decisions, we rest in peace, no matter what happens. Peace should accompany all that we do.
I'm not saying that we won't be discontent if something's wrong. God has given His Holy Spirit which guards us and, by His empowerment, protects us from evil. But we shouldn't be hoping for some supernatural feeling of "peace" in order to guide our decision-making. It almost feels like we're trying to fleece God.
As to what should guide our decisions, the answer is easy. Scripture, faithfully interpreted and applied.
2 Timothy 3:16-17
16All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, 17that the man of God[a] may be competent, equipped for every good work.All Scripture is profitable... that the man of God may be competent, equipped for every good work.
7The law of the LORD is perfect,[a]So let's listen to God where He's spoken clearly already. Let's trust Him at His Word. Let us cry, like David says in Psalm 130, "I wait for the LORD, my soul waits,and in his word I hope;"
reviving the soul;
the testimony of the LORD is sure,
making wise the simple;
8the precepts of the LORD are right,
rejoicing the heart;
the commandment of the LORD is pure,
enlightening the eyes;
9the fear of the LORD is clean,
the rules of the LORD are true,
and righteous altogether.
10More to be desired are they than gold,
even much fine gold;
sweeter also than honey
and drippings of the honeycomb.
11Moreover, by them is your servant warned;
in keeping them there is great reward.