I am not ashamed of the gospel, because it is the power of God for the salvation of everyone who believes: first to the Jew, then to the Gentile. Romans 1:16
If we are ashamed of the gospel it is because our focus is still on us, and not on God.
People have no problem talking about how great a certain college or pro sports team is. Or about how their favorite make of car is the best. Yet, when it comes to the power of God’s gospel, we are reluctant to say anything because we might offend somebody. In other words, we want to convince others about our preferences in things that have no eternal significance, but remain silent about the one thing that can keep them from an eternity in hell.