Is it Biblical tp speak out and warn about heterdox and heretical teaching inside the church? Absolutely. The Bible warns against false teaching in several passages, notably in 2 Peter 2:1-3, which describes false teachers that will infiltrate the church and secretly introduce destructive heresies and exploit believers. 1 Timothy 4:1 warns that some will depart from the faith, following deceitful spirits and demonic teaching. In defending the faith, apologetics must also speak out against false teaching inside the church.

The Christian Research Institute (CRI) has in-depth analysis here of the teaching of Andy Stanley.

“Undergirding Stanley’s arguments, however, lies an anthropology, soteriology, and doctrine of revelation in direct conflict with what God has revealed. Stanley’s program for winning the post-Christian back to Christianity, ironically, strips the church of her most powerful instrument for evangelism, discipleship, and apologetics: the Word of God.“