I did not see the clip, but if John MacArthur is going to rebuke Joel Osteen he should do it privately, if he is lead by God to do so. When things like this are done publicly, rebuking others with so many observing, it hinders the body of Christ. Some of you think that Paul did this but he never did. He knew Peter and rebuked him to his face before all because Barnabus was carried away with the hypocrisy of certain Jews concerning circumcision, but it was done and kept in the local church at Antioch (Gal 2:11-14).
Don't forget what Paul also said in (Phil 1:15-18)...
15 Some indeed preach Christ even of envy and strife; and some also of good will:
16 The one preach Christ of contention, not sincerely, supposing to add affliction to my bonds:
17 But the other of love, knowing that I am set for the defence of the gospel.
18 What then? notwithstanding, every way, whether in pretence, or in truth, Christ is preached; and I therein do rejoice, yea, and will rejoice.
Instead of rebuking others all the time, why not take what they do preach that honors Christ, the gospel message or the word of God and rejoice in it. John MacArthur has some room to grow in grace and knowledge of Christ. He should rejoice whenever the gospel is preached and sinners are pointed to Christ for salvation, even if is only a message of good will.