John 13:35

By this shall all men know that you are my disciples Your loving one another sincerely and fervently, and in the manner and degree I now enjoin, will be the most acceptable and the most ornamental token of your relation to me, and the noblest badge of your profession. The reader will not need to be told how remarkably this new precept of our Lord was exemplified in the spirit and conduct of the first Christians, when he recollects their historian has attested, (Acts 4:32,) that though they were a great multitude, consisting of many thousands, they were all of one heart and of one soul; insomuch that not any of them accounted any of the things which he possessed as his own, but they had all things in common. And the ancient apologists for Christianity inform us, that the persecuting heathen themselves could not help exclaiming in rapture, on observing the prevalence of this grace among them, See how these Christians love one another!