Peter continues to exhort believers to take action in their lives, particularly to put away certain attitudes or traits from their lives. Hypocrisy is still one of those traits Christians are known for. The command to not be a hypocrite has been around for a long, long time! Yet today it is no different than in Peter's day - many people are claiming to follow Christ but have no true relationship with him. This only muddies the waters for Christians and non-Christians alike to try and discern who is really "walking the walk". Verse 2 seems to give us one indicator of a sincere Christian seeking spiritual growth: long for the pure spiritual milk of the word. Just as an infant knows they are in serious need of something, so we need also to instinctively know we are in need of God's Word in our lives. Peter's "if indeed you have tasted that the Lord is good" is almost a bit of a jab... he's making sure people understand that what God is after isn't a moral code of obedience but a "tasting" - an experiential knowledge - of God's goodness.
Then Peter gets into a prominent theme in Jewish culture: that of the corner stone. The corner stone was the stone that was in a certain place in the structure of any building by which everything else was built. It had to fit perfectly, having exactly the right dimensions, or it would cause the whole building to be built poorly. Peter takes what would have been a common imagery in Jewish construction, as well as a popular concept in the Old Testament, and applies it to Christ. Christ is that corner stone on which the Church would be built. Not only that, but we also are living stones, being built into a spiritual house as we all are put into place to be in line with the Cornerstone. The picture is remarkable. Christians don't need a temple... they ARE part of the living temple of God! Christians don't need a sacrificial system... THE sacrifice has already been made for them and now they make spiritual sacrifices in the name of Jesus, giving glory to God. Christians don't need priests to pray for them... We have a High Priest in Heaven and we are a collection of priests, a "holy priesthood" together coming before God in Jesus' name. This also means we can't escape under the guise of "It's not my responsibility to know Scripture and point people to Jesus, that's the professionals' job." We each are responsible to know God is good, to be able to put to words what He has done, and to represent him as priests represented God for Israel.
Peter goes on in vs. 6-8 to quote the Old Testament, showing that God had planned this all along. The "stone", or person, that would be rejected would become the cornerstone of all truth, the cornerstone of faith, the cornerstone of all hope, and the cornerstone for the spiritual house that every Christian is a part of. God always has wanted faith and not just sacrifice. God has always promised us that many will reject him but that this does not make it any less true.
Thank you Lord for being rejected and yet for being the cornerstone. Help our feeble and weak spirits to know that YOU are good, that you are the cornerstone, and that we together are being built into a spiritual house in line with the Cornerstone. We are priests together on a mission to add more building blocks to the house for your glory. Amen