2 John 1:13 greets from an 'elect sister' church, exactly echoing the greeting from 'she who is elect' in 1 Peter 5:13.

Colossians 4:10 identifies Mark as Barnabas's cousin and gives instructions about him, deepening the profile of Mark in 1 Peter 5:13.

Revelation 18:2 uses Babylon symbolically for fallen Rome; 1 Peter 5:13 likely employs the same code for the church's location.

Acts 12:12 introduces John Mark's family home, providing background for the Mark Peter calls his spiritual son.

Acts 12:25 records John Mark's return with Barnabas and Saul, further identifying the Mark mentioned by Peter.

2 Timothy 4:11 shows Paul's high regard for Mark, reinforcing the importance of the Mark Peter mentions.