Three elements of personality are involved in making a decision to become a Christian, or in making any significant decision for that matter. They are the emotions, the intellect, and the will.
For example, a young man meets a young woman. They are immediately attracted to one another. They both say to themselves, "Now there is someone I'd like to marry." At that point, if the emotions had their way, there would be a wedding. But the intellect intervenes, questioning the impulsive emotional response. Would we be compatible? What is she really like? Can I afford to support her? Both conclude it would be better to take some more time and answer a few questions before they proceed. So the two begin spending more time with each other. He eventually concludes that she is as beautiful on the inside as she is on the outside. Now his intellect has sided with the emotions on the idea of marriage.
But the final and heaviest vote remains to be cast -- that of the will. It stops the march toward the altar with the questions, "Am I willing to give up this lifestyle for another? What about my freedom -- is it worth the trade? Am I willing to assume the added responsibility?" The marriage will occur only when the will finally agrees with the emotions and the intellect. And so it is in coming to Christ.
Jim Peterson, Living Proof, NavPress, 1989, p. 170.