The Gemara in מכות comments on why Hashem ultimately allowed Bilaam to go with Balak after He told him not to go. The message here is בדרך שאדם רוצה לילך מוליכין אותו מן השמים. The direction which one wishes to go, is where he is led from Heaven.
This is very much in line with the idea that הכל בידי שמים חוץ מיראת שמים, all is from Heaven, except fear of Heaven. The concept of free will is often misunderstood. While so much of our lives is in Hashem’s hands, we do make certain basic decisions. These decisions are specific to the path we choose to take.
If one desires holiness and spirituality, Hashem will set things in motion that we be able to acquire such holiness.
In Bilaam’s case, he was interested in the wealth promised by Balak. When G-d saw this, it was as if He said, “You made the choice. I will honor your decision and let you go. But because it’s the wrong decision, you will live to regret it.”
We make the major decisions in our lives by way of our free will. We only have to hope they are the right ones in the eyes of G-d.