The church is modeled after a miniature gothic stone cathedral and is surrounded by stone walls. It was built in a Gothic Revivalist style, a design that was copied in wood and brick in small towns across Ontario. The architect, Thomas Fuller, later designed and built the original Houses of Parliament in Ottawa, though only the library remains today. Construction on the church began in 1858, but was halted when the Coleman family, who had taken on much of the financial burden, faced financial difficulties. As a result, the uncompleted church sat for years while the Anglican congregation worshiped in other area churches.

Construction resumed in 1864, and the church was finally completed in 1869. The stone for the church was sourced from quarries in Lyn and Brockville, and members of the church congregation helped transport the stone to the site. Behind the church is a notably large cemetery, containing graves of Lyn area residents dating back to the early 1800s and continuing to the present day.

St. John’s is a small yet active congregation, deeply rooted in the tradition of rural churches in the Diocese of Ontario. The congregation gathers weekly for worship, led by both clergy and a dedicated group of lay readers.

The church also has an active Anglican Church Women (ACW) group that supports the congregation through fundraising and pastoral care. The ACW extends its outreach by supporting important groups and ministries within the community.

The congregation as a whole is committed to contributing to the local community. Their efforts include supporting the local school and sponsoring a children’s softball team in the Lyn Minor Softball League.