1 Pet 2.4-5: "Coming to Him as to a living stone, rejected indeed by men, but chosen by God and precious, 5 you also, as living stones, are being built up a spiritual house, a holy priesthood, to offer up spiritual sacrifices acceptable to God through Jesus Christ."
The picture is that we are a temple, made of stones. Jesus is the cornerstone, with the right shape and position. All the rest of the stones follow His pattern. He is the master builder, who knows what is needed in each stone. He knows your deeds, your faithfulness and your failings. So He is chiseling and sanding away on each of us. It is the sin in us that keeps us from fitting together well as His temple, and that prevents pure sacrifice to God. Let us admit to Him that we don’t meet the design specifications and return to the shop for further work. We do this not so we can be the best stone on the worksite, but so we can fit well with our neighboring stones, bringing harmony, joy, beauty and true worship offered to God.