The issue here isn't whether the cross or the giving of the Holy Spirit came first. Everyone knows that the cross came first. You take issue with my view that the cross was an opening, albeit crucial and critical, salvo against the powers of darkness but the powers of darkness weren't defeated at the cross. From my perspective, the powers of darkness continue to be very real, and just as deadly and I would be a fool to walk around pretending that its all good. If the cross defeated darkness, what accounts for the Apostolic warnings such as "Your adversary, the devil, prowls around like a roaring lion, seeking someone to devour"? Of course, our concern with the devil isn't a threat of being eaten alive, but a deeper, darker threat of being turned to do the will of darkness.
In order to do this, the cross can't simply remain a historical fact, it has to become an everyday reality in each individual person. Each of us individually and personally must constantly wage war against the powers of darkness and remain ever vigilant, guarded against the lies, the deception that comes our way each day. The war won't be over until each of us would rather believe the truth instead of the lie, but frankly speaking, many of us couldn't identify a lie if it bit us in the butt. The works of the devil won't be defeated until the devil has no one else to work on.