Jesus is the living Stone. He was chosen by God and is precious to Him. He is also precious to all those who believe in Him. Those who put their trust in Jesus will never be put to shame. When we come to Jesus, we become like Him. We become as living stones that God is building into a spiritual house (1 Peter 2:4-7). In that spiritual house, Jesus is the cornerstone.
When we follow the cornerstone, Jesus, He provides a firm foundation. When we follow Him, we are called out of the darkness of this world and into the glorious and wonderful light of Jesus. And, when we live in that light, we become a chosen people. Because of God's great mercy, we are the elect, chosen by God to take our place among a people who will serve Him. We become a holy nation, set apart for God and for His kingdom. We are set apart to proclaim the good news of salvation for which He deserves all glory and praise. When we live in the light of Jesus, cleansed from the sin that once separated us from God, we are also a royal priesthood. (1 Peter 2:9)
In the Old Testament, the priesthood was made up of the descendants of Aaron. The role of the priests was to offer sacrifices and to intercede to God for His people. The people could not go before God on their own. But now, because of the atoning sacrifice of Jesus on the cross, all who believe in Jesus, repent of their sins, and follow Him as Lord and Savior, are made part of a royal priesthood. No longer do we need a priest to sacrifice for us. The great High Priest, Jesus, has provided that sacrifice, once for all (Hebrews 7:27). No longer do we need a priest to approach God on our behalf. As part of the royal priesthood, we can go before Him on our own.