1 Corinthians 4:7
For who sees anything different in you? What do you have that you did not receive? If then you received it, why do you boast as if you did not receive it?
We all received the Gospel. No one is a Christian by any other means than by hearing the Gospel of Jesus Christ and believing it. You were not born knowing it. It had to be delivered to you. In that regard, all Christians are alike.
It is a great leveller.
So why do you boast as though you did not receive it?