First of all, I would like to say that what I am going to write here are nothing but my humble theories about this subject. This is not based on any readings or other people's ideas. It is just stuff that comes to my mind. As a consequence it is all very simple and probably a bit naif.
I believe that God has a plan for His children's lives. I also believe that He does not have a detailed plan all organized and that He is not totally responsible for the completion of that plan.
I am going to try to explain this with two important decisions in a person's life: the choice of a career and marriage. Imagine that God's plans for some man are that he becomes a scientist and marries a good, wise, honest girl that is going to love him for the rest of his days (lucky guy!).
This man may be wise and understand God's cues and do what God planned for him the easiest way.
Or, he may be a fool. He may, for example, prefer a job that pays him a lot of money to a job as a scientist, even though he feels that being a scientist is what really gives him joy and fulfilment. If that is the case, I believe he will face barriers somewhere along his way. He may never get the well-paid job he wants and end up coming back to science (in which case he was lucky) or he may get a job that makes him rich and miserable, because he is not really doing what he loves.
More or less the same applies to the marriage. I do not believe that God wants us to marry a specific person, especially because marriage is an act that involves two wills. But imagine that this same scientist man that was supposed to marry a nice, wise, sensible woman only falls in love with crazy, selfish women and does not even see the nice, wise, sensible girls that God puts in front of him. Then he is in trouble. Either God let's him marry some crazy woman and allows him to be miserable for the rest of his days, or He will pitty the poor guy and somehow create obstacles to his unwise relationships. Or a mix of both, until he learns what he is supposed to do with his life.
So basically I believe that God has a general plan for our lives that would be like a long sunny road, with no holes and with trees, flowers and fountains all along it. But I also believe that we may get away from that road, enter the desert, get lost and never find our way back again.
