Revd Les Isaac, helped found the organisation Street Pastors in 2003 to reduce inner city gun and knife crime.
His call comes as yet another teenager was stabbed to death in London this year.
In January, The London Evening Standard reported a general rise in knife crime in London- 15 teenagers were stabbed to death in 2015, the highest level in seven years.
The paper also reported high levels of stabbings between 2012 and 2014, a total of 9,666 across the city.
Les Isaac says community organisations are shutting down and funding is drying up for programmes that work with young people to discourage knife carrying. Speaking to Premier he suggested there is a culture of knife crime and young people often feel they must carry a knife to be safe.
He said: "They are caught up in knife culture, and many are desperate to get help, but there is no one there, consistently working with them to help them out of this culture."
Along with Street Pastors, Les Isaac also started a project called Word for Weapons, which strategically places knife bins so people can hand in knifes anonymously. The initiative has already collected over 22,000 knives across London and West Midlands.
His final appeal for help is to churches: "One young man told me once, we have enough bad people on the streets; we need more good people on the streets.
"I'm challenging, particularly people from the church to get involved...it could make a significant difference for young people."
Listen to Les Isaac speaking to Premier's Megan Howe.