living together prior to marriage

Question from Sophie on 1/25/2008:  
Many couples nowadays that live together outside of marriage are being married in the Church without requiring them to separate. The reason given is that it is so widespread that if they did not they would lose many to the Catholic Faith. Isn't this attitute lacking in faith and going against the teaching of Jesus? Jesus taught that if one is sinning, talk to him. If he does not listen get 2 or 3 or the whole Church. If he still doesn't listen, do not assocate with him. Please explain.
Answer by Fr.Stephen F. Torraco on 2/1/2008: 
People preparing for the reception of the Sacrament of Marriage should be doing so in accord with the Church's teaching that cohabitation prior to marriage is unacceptable and immoral.