It's another fine Spurgeon quote entitled Unity at all costs?, and here's an extract:
The largest charity towards those who are loyal to the Lord Jesus, and yet do not see with us on secondary matters, is the duty of all true Christians. But how are we to act towards those who deny his vicarious sacrifice, and ridicule the great truth of justification by his righteousness? These are not mistaken friends, but enemies of the cross of Christ. There is no use in employing circumlocutions and polite terms of expression:where Christ is not received as to the cleansing power of his blood and the justifying merit of his righteousness, he is not received at all.