Church leaders have called the government's Gambling White Paper a "combination of welcome changes, disappointing delay in some important areas, and missed opportunities".
In a joint response, the Baptist Union of Great Britain, the Church of Scotland, the Methodist Church and the United Reformed Church highlighted advertising as an area that requires tighter controls.
It is a "powerful tool for normalising gambling, particularly around sport", they said.
The government has said it wants to consult further on protections for young adults, including introducing enhanced checks and limits on online stakes.
Although the direction of travel in the White Paper was said to be "encouraging", the Churches expressed frustration about the three-year wait for its publication and the decision to hold more consultations, meaning "further delay and dilution".
"We cannot afford further delay, and encourage the government to ensure that gambling is indeed a public health priority," they said.
The Church added that the "limited consultation on marketing and voluntary codes" has led to a missed opportunity for the government to do more to reduce harm caused by gambling among young adults and those in difficult circumstances.
Young people aged 18-24 have the highest rates of problem gambling, the response from the Churches notes.
The concerns raised in their response echo those of Christian campaign group CARE, which has also expressed dissatisfaction with delays to gambling reform.
It is campaigning to put a stop to gambling advertising and sponsorship in football, and says there is "no need" for more consultation on reforms.
