Summary: God will guide you but he'll use your rational mind as much as special intervention but he expects us to make decisions according to his revealed will.
I recently bought one of these new smart phones. It's great. It does everything, except make the coffee. One of the best “apps” on it is the navwoman. You type in your destination and a very clever woman tells you exactly how to get there. “Turn right in 300 metres.” “At the roundabout take the second exit.” And she’s very forgiving. If you miss a turn she calmly says “Recalculating.” I mention this because this is how some Christians expect God to guide them. At each decision point he’ll tell them which way to go. If they make a mistake or ignore his prompting he’ll simply forgive them and recalculate their path.
Well, there’s some truth to that perhaps. God’s sovereignty does override our sinfulness. You can see that in the history of Israel and of the Church. God certainly promises in various places to guide us. Jesus promises his disciples that when he goes he’ll send them another counsellor to be with them, the Holy Spirit who'll guide them into all truth.
But does that mean that God will tell you which way to go at every decision making point? Does God have a wonderful plan for your life that you need to find if you're to be happy?
How does God Guide us?
Well, before we answer that question lets look at a few of the many passages that talk about God teaching us how we should go. Psalm 32:8 (quickview) : “I will instruct you and teach you the way you should go; I will counsel you with my eye upon you.” In the passage we just heard the psalmist says “Good and upright is the LORD; therefore he instructs sinners in the way. 9He leads the humble in what is right, and teaches the humble his way” (Ps 25:8-9). In Is 30 we read “20your eyes shall see your Teacher. 21And when you turn to the right or when you turn to the left, your ears shall hear a word behind you, saying, ‘This is the way; walk in it.’”
But what do you think, is God talking about showing us the right decision to make at each turn, or something else?
What I want to suggest is that in almost every case God's talking about showing us how to live according to his will. In Ps 25 when he talks about turning to the right or to the left he means turning away from God's way of life. In Psalm 32 (quickview)  he leads the humble in what is right; that is, in what is pleasing to God.
God will guide us, but he’ll guide us first of all in the way of right living. God has given us his word to instruct us. The Psalms are full of this sort of instruction. Ps 119:104-105: “Through your precepts I get understanding; therefore I hate every false way. 105Your word is a lamp to my feet and a light to my path.” Again, from Ps 25: “10All the paths of the LORD are steadfast love and faithfulness, for those who keep his covenant and his decrees... 12Who are they that fear the LORD? He will teach them the way that they should choose.” Notice it’s not he will tell them what to do. It’s he will show them the way they should choose.