Just before 1973, the folks considering splitting completely off from the mainline Presbyterian church looked for where the core doctrines had been abandoned.
The symptoms of that abandonment were abounding: Using Tithes to fund the Communist Sandanista Rebels and also to transport young Women across state lines for Abortions was too much to bear. So they examined the past and found other red flags and ultimately the core doctrinal abandonment that caused them.
The other symptom was in the 1930's in ordaining a minister who did not believe in the resurrection of Christ.
Ultimately it came down to the core doctrinal change, that of abandoning Biblical inerrancy.
The symptoms in any church ultimately comes down to faith in God, His Word, and His authority. And since the current depravity seen is no different and the need for sincere repentance is ever more evident - Severe prayers are indicated.
Our PCA church announced that, unlike the PCUSA, they voted to reaffirm the defense of marriage. While there was no dancing in the aisles, there were sustained and enthusiastic applauses.