Ensure that your contractor carries out a full risk assessment before undergoing each job. It is your responsibility, as the person engaging the contractor, to ensure that other risk assessments and safe systems of work are in place, in order to comply with your duties under the Management of Health and Safety at Work Regulations.
If the work is construction or building work, as the client you have duties under the Construction (Design and Management) Regulations 2015.
Take a look at the HSE guidance on using contractors for construction work: HSE Guidance on using contractors for construction.
You should consider providing an induction before a contractor comes on site to make them aware of:
It is important to inform any employees, tenants, and regular visitors that contract work is taking place, identifying any overlaps that may affect health and safety. Informing local residents when building work is taking place can also increase security.
If the place of worship is having major building works or scaffolding is being erected, it is important that you contact your insurance provider to ensure that your church insurance is adequate. They may reduce cover and apply additional terms and requirements to your policy.
You will also need to consider The Work at Height Regulations for any such work being undertaken. If you are an employer or you control work at height (for example building owners who may contract others to work at height) the Regulations apply to you.