3:16 out of my mouth. Note that Christ would prefer not only a hot church like Philadelphia but also a cold church like Sardis to a lukewarm, neutral, accommodationist, comfortable church like Laodicea. At least Sardis was not harming anyone because it was not influencing anyone.
3:17 have need of nothing. There are multitudes of large and affluent churches today that are evangelical and nominally Biblical. They have become so comfortable with evolutionism and modern life styles that they are spiritually impoverished, filled with half-converted babes in Christ who are easy prey for the world, the flesh and the devil. The Lord is calling them to repentance (Revelation 3:19), for they are still His churches, and therefore He must rebuke and chasten them sooner or later.