Still, in pushing for a "unitive vision of evangelicalism" (the name of chapter 10 in his book), nonetheless Lovelace does have a section (in chapter 10) entitled, "When Separation is Necessary." Lovelace writes, "Despite the desirability of remaining within seemingly apostate bodies to work toward their renewal, it must be recognized that separation is sometimes necessary..." (Dynamics, p. 309).
The first occasion for separation as Lovelace writes is in those instances when the parent body perpetually violates the consciences of its members or restricts practices in essential areas. As a caution, in such cases, it is of the utmost importance that the group determine if the issue over which the schism occurs is of "ultimate importance." To what extent is the parent body so terminally ill so as to be jaded to the liberty purchased for us by Christ? in essence to have lost a hold of the Gospel itself (Galatians 5:1)? The analogy of amputation is used when it is necessary to cut off a limb where there is gangrene, for example; but what if the entire parent body is cancerous?
In addition to a parent body being terminally ill, the second occasion Lovelace says is when there is "unequal yoking" that hinders the "maximum working efficiency of the church by crippling some of its members" (Dynamics, p. 310). The example is given within my own Presbyterian history when J. Gresham Machen left Princeton Seminary in 1929; Lovelace says had Machen not done so, "...the Evangelical movement in America in this century (20th) would have been considerably impoverished":
The subsequent withdrawal of Orthodox Presbyterianism from the mother denomination constituted a disastrous loss of white corpuscles from the parent body. But it also saved the denomination from tearing itself apart in an allergic reaction, a spiritual equivalent of the disease called lupus. The isolated leukocytes went their way in less than optimal health, occasionally turning on one another in counterproductive attacks which showed that not all the fault was in the parent church. But their isolation did enable them to maintain a form of biblical orthodoxy with integrity of conscience, although not always with the balance and catholicity which continuing involvement with other leaders would provide. Their witness formed a plumb line for the rest of Evangelicalism, reminding it of the fallibility of modern innovations and holding before it an ideal of absolute fidelity to Scripture, even though this ideal was imperfectly attained. In many respects they lost contact with the real situation in the mainline denominations whose thrust they continued to challenge, and their prophetic witness to these denominations at times became uncharitable and parochial. But they did preserve their distinct approach, … and they too are sprouting new leaves and bearing fruit in the midst of the present renewal. Dynamics, p. 311
I cannot begin to express how much I appreciate these words of Lovelace's as they tap into some of my most deeply-held existential questions regarding my being Evangelical and Presbyterian. For one, Lovelace acknowledges the central importance of Machen and his split from both Princeton as well as the mainline Presbyterian church later in the 30s. Lovelace describes how Machen served as a "plumbline" for all Evangelical Christians regarding fidelity to Scripture. But Lovelace then goes on to acknowledge that this ideal/plumbline was "imperfectly attained," that Machen's prophetic witness at times was uncharitable and parochial and that he often lacked "balance and catholicity." Wow. I don't know how to express this fully, but I needed to hear this. I needed to hear about both the great contributions of my Presbyterian forefather as well as have someone acknowledge his failures as well; Lovelace did both. Wow. I am part of the fruit of Machen's work for which I am grateful, but also I know the seeds of that fruit were sown imperfectly.