What does the Bible say about the church being dead and dying?

In Revelation 3:1-6, the church at Sardis is described as having a name that it lived, but it is dead. This speaks to the condition of many churches today that may appear vibrant on the outside but lack spiritual life on the inside. The church's works reveal its true state, and Christ critiques them for being merely a profession of faith without the corresponding reality of regeneration and true faith. The spiritual deadness of Sardis serves as a warning for believers to examine their own faith and the health of their local church, urging vigilance against complacency.