Mainstream Christianity is the many roads that lead to destruction, the many roads that lead to hell. It is the broad road Christianity and many are on it. The true followers of Jesus Christ have never been pew sitters, they have never been part of mainstream Christianity, they were always rejected and persecuted. They were not with the crowds, they were walking the lonely road with Jesus.
If you follow Jesus Christ you do not become part of a group, you become part of the Kingdom of God and you are led by the Holy Spirit. He takes you on the lonely road of righteousness, holiness and obedience and you are persecuted by the fake Christians in the churches. If you seek the approval of Jesus Christ you will not be part of mainstream Christianity. You will be part of the Kingdom of God. LISTENING to the Holy Spirit, seeking Jesus all the time, going after Him, being where He is and DOING what He tells you to do. You will be the LIGHT OF THE WORLD, the SALT OF THE EARTH, rejected and persecuted like He was. You will be LIKE HIM, you will not be like mainstream Christianity.
Are you following Jesus Christ and doing His will or are you part of a church club that is on its way to damnation? If you want eternal life you have to follow Jesus Christ on the straight and narrow way and do His will, be pleasing to Him.
May Jesus bless you.