If you ask, why does the church SEEM to be sexist, sometimes it is because of sin; and sometimes it makes distinctions, because Jesus did. While there are sins that happen within the church and among Christians, that is not an accurate representation of Jesus, it is a misuse of his name. Jesus himself gave authority to preach and teach to the 12 disciples, who were all men. God has made a distinction between men and women, when it comes to authority in the church.
Reference: Matthew 10
