The Gospel is good news meant to be shared with others. You cannot “keep” the Gospel for yourself; it is meant to be given away to all people.
Jesus speaks to His disciples in multiple environments about the need to proclaim the Gospel, to let others know about the good news. This is our invitation from Jesus as well: to proclaim the Gospel to all people. This means talking with people about Jesus and sharing how Jesus has transformed and is transforming our lives. Our faith is not intended to be private or secret but to be lived publicly in front of others.