Contend earnestly for the faith which was once for all delivered unto the saints...

Jude 1:3b.

The following quote was put forth by a commenter at Old Life as a defense of the Roman Catholic Church, and as an indictment of the Reformed churches that parted ways with Rome in the 16th century.

"If you must make a choice between heresy and schism, always choose heresy. As a schismatic, you have torn and divided the body of Christ. Choose heresy every time.” 

- Rev. James I. McCord, Presbyterian leader in the ecumenical movement and longtime president of Princeton Theological Seminary

Then logically on that basis, a completely heretical church is preferable to a doctrinally pure schism?? Please... And this is not said to defend schisms.

The schism condemned in the Bible is that which begins with a departure from the doctrine of faith handed down by the apostles as recorded in the Scriptures, not merely a break away from some outward organizational structure of the church. A fixed departure from truth into heresy or error would ultimately result in outward schism. So the concern of the apostles was the preservation of pure doctrine. Those that did depart from the apostolic faith as recorded in God's Word were those who were judged as schismatic. Thus the verdict of the reformers during the 16th century Reformation was that Rome, at the Council of Trent in 1563, departed from the faith which was once for all delivered unto the saints. In officially separating herself from pure doctrine, Rome separated herself from the true church. In effect, Trent was a schismatic document.

As set forth in Scripture the unity of Christ's church, which is his body, is not measured by something solely outward, nor is that unity maintained apart from holding fast to Christ’s true faith. To argue for Rome’s claim as the one true church on the basis of organizational history or succession of bishops sadly ignores the centrality of the gospel of Christ. And it was that gospel that Rome rejected at Trent (see Canons). The gospel declares that sinners are saved by grace alone, through faith alone, in Christ alone. It is the power of  God unto salvation for the lost (Rom. 1:16). And that gospel message is the means by which God establishes the church of Christ and the ground upon which He nourishes and maintains it. Without the true apostolic faith there is no church.