Re: “So if someone is preaching a heresy like the prosperity gospel, we should just let them?”
If someone is preaching doctrine that is heretical to Biblical teaching in your church or my church or on the street corner or in a public forum, then yes, absolutely it must be confronted. That is not what happened here. This was in a church (what kind I do not know) that apparantly invited Mr Olsteen to speak during their worship service - that is not the appropriate time to or place to confront him - unless you are the pastor or member of that particular church.
There are religious groups that meet all the time whose doctrine is heretical according to Biblical teaching (Jehovah’s Witnesses, Christian Science, Unitarian, etc.) - but it is on their property and I have no business or legal right to trespass on their turf and disrupt their services. And, again, what goes around, comes around.
There is a time and a place for vigorous debate but not during someone else’s worship service. Religious freedom is not a one-way street. If you want the freedom to worship God as you see fit, you must allow even those you disagree with the same freedom - especially on their own property.
It was Osteen’s house of worship.