After hearing both sides of the case, it seems as if Felix was fairly certain of Paul's innocence, but perhaps his fear of the people made him unwilling to stick his neck out and set the prisoner free. Instead, he gave him quite a bit of freedom, but kept Paul in prison for another two years.
During that time, Felix sent for the apostle often, so that he could speak with him about the Christian faith. It even sounds as if he was fairly close to being convinced of the truth of the gospel, and that made him frightened. On one occasion, he sent Paul away, saying that he would call for him again "when it is more convenient."
There are probably plenty of people like that in the world today. Deep down, they actually believe that God exists, and they are intellectually persuaded of the truth of His claims, but they put off the decision for later, instead of making a commitment now.
But the truth is, it is never convenient to commit to Jesus; it is always going to disrupt our lives and turn things upside down, as He changes our priorities and our value system. Perhaps the most important question we will ever answer in life is whether we are willing to embrace that divine and dynamic disruption.
Sadly, greed and self interest also played a role for Felix. The text tells us that he kept inviting Paul to dialogue, because he hoped that there would be a bribe in it for himself. Likewise, many people today are more interested in, "what's in it for me?" and so they miss out on the most desirable disruption the world has ever known.
