J. C. Ryle, Old Paths (London, 1898), 259:
The cross is the grand centre of union among true Christians. Our outward differences are many, without doubt. One man is an Episcopalian, another is a Presbyterian,—one is an Independent, another a Baptist,—one is a Calvinist, another an Arminian,—one is a Lutheran, another a Plymouth Brother,—one is a friend to Establishments, another a friend to the voluntary system,—one is a friend to liturgies, another a friend to extempore prayer. But, after all, what shall we hear about most of these differences, in heaven? Nothing, most probably: nothing at all.
Does a man really and sincerely glory in the cross of Christ? That is the grand question. If he does, he is my brother: we are travelling on the same road; we are journeying towards a home where Christ is all, and everything outward in religion will be forgotten. But if he does not glory in the cross of Christ, I cannot feel comfort about him. Union on outward points only is union only for a time: union about the cross is union for eternity. Error on outward points is only a skin-deep disease: error about the cross is disease at the heart. Union about outward points is a mere man-made union: union about the cross of Christ can only be produced by the Holy Ghost.
(HT: Tony Reinke)
Already Not Yet 
Reblogged this on Justification by Grace and commented:
The cross of Jesus Christ! Christ and Him crucified. The very center of our worship and praise; the key of our interpretation of all scripture; the truth that unites us despite our differences. Our beloved brother, Peter, reminds us of those truths and more through this tremendous quote by J.C. Ryle at his blog, “Already Not Yet.”
What a wonderful blog! Found you by way of Jon Cardwell’s, Justification By Grace. I love how your last 2 posts complement one another! Pleasure to meet you and have a beautiful Lord’s Day!