I noticed that Reformed Musings had a post on the topic of the relation between crime and gun-control (link). The relation, of course, is that as gun control tightens, crime (including crime involving guns) increases. Now, as Reformed Musings noted, Britain has started implementing more expansive weapons searches that look for knives (the new weapon of choice for British thugs).
Even if knives could be controlled (and frankly, considering that prisoners in jail are able to find ways to make knives and stab each other, that does not seem possible), the crime would not stop. Criminals would just resort to other techniques and weapons.
What they cannot do at security checkpoints is check the hearts of men. The heart of mankind is desparately wicked. In British society of 100 or 200 years ago, this wickedness was largely held in check by the effect of the Gospel and the Holy Spirit on a large portion of the populace. It was a Christian society, and even men with wicked hearts were under social pressure to act like Christian men (i.e. to be hypocrites, rather than openly wicked men).
What then is the solution in a wicked society? The solution is that outlined by Christ to his disciples in preparation for the collapse of society in his day:
Luke 22:36 Then said he unto them, But now, he that hath a purse, let him take it, and likewise his scrip: and he that hath no sword, let him sell his garment, and buy one.
And, at the same time, fight the collapse by spreading the Gospel. Although a sword may save your life, it may do so at the cost of your neighbor's life. But the Sword of the Spirit, the Word of God, is able to save your life and your neighbor's life.
1 Timothy 2:1-2
1I exhort therefore, that, first of all, supplications, prayers, intercessions, and giving of thanks, be made for all men; 2For kings, and for all that are in authority; that we may lead a quiet and peaceable life in all godliness and honesty.
14Ye are the light of the world. A city that is set on an hill cannot be hid. 15Neither do men light a candle, and put it under a bushel, but on a candlestick; and it giveth light unto all that are in the house. 16Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.
Even so, let us proclaim the gospel and enlighten the world around us, even while taking prudent precautions for the defense of our lives and the lives of our family and neighbors.
P.S. I found it interesting that Reformed Musings categorized the post in question under "Federal Vision." I didn't quite see the connection.