Thou art of purer eyes than to behold evil, and canst not look on iniquity: wherefore lookest thou upon them that deal treacherously, and holdest thy tongue when the wicked devoureth the man that is more righteous than he? (Habakkuk 1:13)just thankful that Jesus decides these issues on who to seperate from here on earth, as you and I will be fellowshipping with those who were labeles Catholics/baptists/methodist/Charasmatic etc for eternity!
Why not get used to it though here and now?
Because I serve a holy God who does not condone sin. If believers and the churches that they go to condone sin then why should I fellowship with them? If their doctrine is in error then they are out of fellowship with God.
God demands holiness--without which no man shall see God.