Examples of church anniversary speeches can easily be found online on websites like Church Pastor Guide, Write Out Loud and Find the Words. Depending on the particular denomination, there may also be church-specific sites for such occasions.
When giving an anniversary speech in a church setting, the speaker should begin by welcoming the congregation and providing a brief history of the church. Names of founding members, earlier church buildings sites and special "stand-out" moments would be important to include in a speech. Inviting former clergy or community members who have a history with the church to speak would also be appropriate for an anniversary speech. Pictures, videos, even old audio files of members praying would provide a potentially special meaning to the congregation.
While an anniversary of a church commemorates a spiritual and sometimes painful history, the speaker could add light-hearted words, as well. Funny memories of Vacation Bible School, church potlucks and softball games, or even examples of church bulletin misprints can make an audience more comfortable, as well as spark other memories that people might want to share.
Knowing why the occasion is special, being mindful of who is in the audience and sharing the church's milestones will make the speech appropriate. Sharing how the church has had a positive impact on the congregation and community will make the speech memorable.