From Martin Downes book Risking the Truth:
Downes:
How have you dealt with church members or students who have been attracted to, or taken in by false teaching?
Michael Horton:
‘Pastoral sensitivity and prudence is required in order to know whether a fellow-Christian needs ‘Law’ or ‘Gospel’. (A terrific discussion of this is found in William Perkins’ The Art of Prophesying.) So an obstinate person who persists in heresy should be warned with the threat of excommunication (as Paul treated the Galatians).
However, a struggling Christian who has been exposed to false teaching must be corrected with patience and love. This person is a bruised reed or a flickering candle, and we know how Christ treats them – for to some degree, we are all in this catagory.’