Usually, yes. A gas system draws almost nothing electrically, so the heat comes down a gas pipe rather than a cable. Move to electric and that whole heating load shifts onto your electrical supply, which raises peak demand sharply even though total energy use may fall.
This catches churches out late in the process, often after a system has been specified. Ask the question early, because a supply upgrade means approaching your distribution network operator, and that can take months and run to thousands of pounds.
It is not always a barrier. Zoned infrared heats only the area in use, so peak demand is lower than heating the whole building, and battery storage can cover short high demand periods from a modest supply by charging when power is cheap.
Get an electrical survey before you choose a system, not after. See what power supply church heating needs.