# But if our gospel is veiled, it is veiled only to those who are perishing
See 2 Corinthians 3:14. There Paul explained that there is a spiritual veil that prevents people from understanding when they read the old covenant. In the same way, people are not able to understand the gospel.
# if our gospel is veiled, it is veiled
"if a veil covers our gospel, that veil covers it"
# our gospel
"the gospel that we preach"