From John Owen’s Commentary on Hebrews 3:15-19
This is a ground of unspeakable consolation unto believers, with supportment in every condition. No unworthiness in them, no misery upon them, shall ever hinder the Lord Christ from owning them, and openly avowing them to be His brethren. He is a brother born for the day of trouble, a Redeemer for the friendless and fatherless. Let their miseries be what they will, He will be ashamed of none but of them who are ashamed of Him and His ways, when persecuted and reproached. A little while will clear up great mistakes. All the world shall see at the last day whom Christ will own; and it will be a great surprisal when men shall hear Him call them brethren whom they hated, and esteemed as the offscouring of all things. He doth it, indeed, already by His word; but they will not attend thereunto. But at the last day, they shall both see and hear whether they will or no. And herein, I say, lies the great consolation of believers. The world rejects them, it may be their own relations despise them—they are persecuted, hated, reproached; but the Lord Christ is not ashamed of them. He will not pass by them because they are poor and in rags—it may be reckoned (as He himself was for them) among malefactors. They may see also the wisdom, grace, and love of God in this matter. His great design in the incarnation of His Son was to bring Him into that condition wherein He might naturally care for them as their brother; that He might not be ashamed of them, but be sensible of their wants, their state and condition in all things, and so be always ready and meet to relieve them. Let the world now take its course, and the men thereof do their worst; let Satan rage, and the powers of hell be stirred up against them; let them load them with reproach and scorn, and cover them all over with the filth and dirt of their false imputations; let them bring them into rags, into dungeons, unto death—Christ comes in the midst of all this confusion and says, “Surely these are my brethren, the children of my Father,” and He becomes their Saviour. And this is a stable foundation of comfort and supportment in every condition. And are we not taught our duty also herein, namely, not to be ashamed of Him or of His gospel, or of any one that bears His image? The Lord Christ is now himself in that condition that even the worst of men esteem it an honour to own Him; but, indeed, they are no less ashamed of Him than they would have been when He was carrying His cross upon His shoulders, or hanging upon the tree; for of everything that He hath in this world they are ashamed—His gospel, His ways, His worship, His Spirit, His saints, they are all of them the objects of their scorn; and in these things it is the Lord Christ may be truly honoured or be despised.