A 17-year-old boy was stabbed to death in Canning Town, east London on Wednesday evening.
Police believe he may have been the victim of what they're describing as a 'sustained and possibly targeted attack'.
He's the third teenager to die as a result of knife crime in the capital so far in 2018.
Michael Smith, CEO of the Christian group Word 4 Weapons tells Premier youngsters need scripture to stay on the straight and narrow.
"Whether the school likes it or not, I quote the Bible. I tell [students] what it says Jesus says," he said.
"We make it absolutely clear that in Matthew 26 verse 52, the Lord said to Peter 'put up your knife in this place because he who lives by the sword, dies by the sword'."
In 2017, there were 80 fatal stabbings in London.
The latest killing comes as both the Mayor of London and Scotland Yard face mounting pressure to bring the city's knife crime problem under control.
Theresa May drew an angry response from Sadiq Khan earlier this month when she suggested that the surge in deaths came after Labour took charge of the capital.
Mr Khan, who succeeded Conservative Boris Johnson to the role, wrote on Twitter: "The PM simply can't be allowed to get away with misleading information.
"Knife crime is rising across Britain - not just London - & started going up well before May 2016. 8 years of Tory cuts to police & preventative services must urgently be reversed."
However, Mr Smith said the Mayor of London isn't doing enough to tackle knife crime.
"Education is something that we push very much at Word 4 Weapons. We encourage people to get educated in the law - get educated on the dangers of knife and gun crime.
"We have been pushing and pushing and pushing for the London Mayor to fund some of our workshops and to fund the knife bins in London and to be honest, we're still waiting in limbo for an answer from the mayor's office... why are they not really doing anything about knife and gun crime when they have made a promise to Londoners that they are going to deal with it?
"We need to pray fervently for our young people, pray for their home life, pray for their upbringing, pray for the teaching that they're getting in school... which is quite immoral."
According to Scotland Yard, the victim of the latest fatal stabbing in London was one of 12 people stabbed to death this year.
The Metropolitan Police said officers were called to reports of a youth with stab wounds at Goldwing Close, Canning Town, shortly after 8pm on Wednesday.
London Ambulance Service paramedics were unable to save the victim and he was pronounced dead at 8.38pm.
No-one has been arrested in connection with the Valentine's Day killing, police said.
Detectives are examining whether an abandoned vehicle found in Freemasons Road, near Victoria Dock Road in east London, is linked to the attack.
Anyone with information is asked to contact the Homicide and Major Crime Command incident room on 0208 345 3775, police on 101, or Crimestoppers anonymously on 0800 555111 quoting ref 8884/14FEB.
Listen to Michael Smith, CEO of the Word 4 Weapons speaking with Premier's Cara Bentley:
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.