Peacocks were adopted by early Christians as a symbol of the Resurrection, referencing the belief that their flesh didn't decay and their beautiful feathers were a reminder of God's grace. The "eyes" on the peacock's feathers also symbolize the all-seeing eye of God. Here's a more detailed look at the symbolism:

Resurrection and Eternal Life:

The peacock's ability to shed and regrow its feathers annually, and the belief that its flesh didn't decay, were seen as metaphors for the Christian belief in the resurrection of the body and eternal life. 

The All-Seeing Eye of God:

The large, ornate eyes on the peacock's feathers were interpreted as a reminder of God's omniscience. 

Christian Faith and Grace:

Peacocks can also be seen as a reminder that a Christian's true beauty is revealed through their faith and grace, rather than just outward appearances.