Who is the stone that was cast aside and became a stone of stumbling?

Les explains that Peter writes these little epistles shortly before he and Paul were martyred, after Paul's revelations had been out a long time. In 1 Peter 2, Peter tells newborn babes to hunger for the milk of the Word so they may grow. Coming to the living stone, disallowed indeed of men, he identifies Christ as the stone cast aside that became a stone of stumbling, especially to Israel, yet chosen of God and precious. Peter also writes to believing Jews of the dispersion—though it applies to us too—that believers as living stones are built up a spiritual house, a holy priesthood, to offer up spiritual sacrifices by Jesus Christ.