If we were to just totally remove everything around us that tempts us or could cause us to stumble, we would not be dealing with the foundation of the issue. Instead we would only be trimming its branches for the time being, but later we will have to trim it back again. How can we turn away from sin completely if we merely remove that which would cause us to sin from our presence? When dealing with an internal vice, we are to not only pray for God to remove that vice, but we ask for him to present us with opportunities to be tempted that we might overcome that sin and grow stronger, thus becoming more like Christ. You cannot force a society into not indulging in immoral acts, and then call that a just society. Instead its justice and ability to overcome temptations has to be tested and proven.