Who gave Himself for our sins, that He might deliver us from this present evil world, according to the will of God and our Father. – Galatians 1:4

When it came to Christ’s death, which was the pouring out of His soul, then His fullness of grace was seen. He was full of grace indeed, forasmuch as He emptied Himself to save men. He was Himself not only man’s Saviour, but his salvation. He gave Himself for us. He was indeed full of grace when He bore our sins in His own body on the tree. His was love at its height, since He died on the cross, “the just for the unjust, to bring us to God.” Pronounce the word “Substitution, ” and you cannot help feeling that the Substitute for guilty man was full of grace; or use that other word, ” representative,” and remember that whatever Jesus did, He did as the covenant Head of His people. If He died, they died in Him; if He rose again, they rose in Him; if He ascended up on high, they ascended in Him; and if He sits at the right hand of God, they also sit in the heavenly places in Him. When He shall come a second time it shall be to claim the kingdom for His chosen as well as for Himself; and all the glory of the future ages is for them, and not for Himself alone. He saith, “Because I live, ye shall live also.” Oh, the richness of the grace and truth that dwell in our Lord as the representative of His people! He will enjoy nothing unless His people enjoy it with Him. “Where I am, there also shall my servant be.” “To him that overcometh will I grant to sit with Me in My throne, even as I also overcame, and am set down with My Father in His throne.”

There is yet another word higher than “substitution,” higher than “representation,” and that is “union.” We are one with Christ, joined to Him by a union that never can be broken. Not only does He do what He does, representing us, but we are joined unto Him in one spirit, members of His body, and partakers of His glory. Is it not a miracle of love that worms of the earth should ever be one with incarnate Deity, and so one that they never can be separated throughout the ages? – C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/1862.cfm