How did the Willow Creek church come to allow and encourage women in leadership?

The [Willow Creek Community Church](https://en.wikipedia.org/wiki/Willow_Creek_Community_Church) has long had a policy of both men **and women** in leadership roles - which was (and is still) counter to what many other churches teach. From [their site](http://www.willowcreek.org/beliefs) : > **We believe churches should be led by men and women with God-given leadership gifts.** This includes the concepts of empowerment, servant leadership, strategic focus, and intentionality ([Nehemiah 1–2](http://www.biblegateway.com/passage/?search=Nehemiah%201%E2%80%932&version=NIVUK) ; [Romans 12:8](http://www.biblegateway.com/passage/?search=Romans%2012:8&version=NIVUK) ; [Acts 6:2–5](http://www.biblegateway.com/passage/?search=Acts%206:2-5&version=NIVUK)) . I'd really like to know how they came to this view and *especially* their Biblical basis for this belief (beyond the verses quoted above which, while they are about leadership, do not mention women specifically).