When speaking of the order of salvation (ordo salutis), Reformed theology always and everywhere insists that regeneration precedes faith. Regeneration precedes faith because it is a necessary condition for faith. Indeed, it is the sine qua non of faith. It is important to understand, however, that the order of salvation refers to a logical order, not necessarily a temporal order. For example, when we say that justification is by faith, we do not mean that faith occurs first and then we are justified at some later time. We believe that at the very moment faith is present, justification occurs. There is no time-lapse between faith and justification. They occur simultaneously. Why then do we say that faith proceeds justification? Faith precedes justification in a logical sense, not a temporal sense. Justification is logically dependent on faith because we are justified; we are justified because we have faith.
Sproul, R.C.; Grace Unknown: The Heart of Reformed Theology; Baker Books; Grand Rapids, MI; copyright 1997; p. 195