The means to sin rests in our bodies–we can’t walk away from our eyes and mind like we can walk away from drugs. This also explains why prayer alone is often not enough for total victory. We can go to the alter of prayer and be freed, but if we stop short and never fully close the gates of our eyes to sensual pollution, the sewage seeps right back in day in and day out. The chemical highs return, and we’re captured again.
While we’re to pray about sexual sin on the spiritual front, we have our orders on the physical battlefront as well. We’re commanded to actively avoid sensual sin by choice–“to flee.” It isn’t unspiritual or “fleshly” to take an active role in this battle and to build defenses. We’re commanded to do so by God. What’s more spiritual than obedience?