16 For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek. 17 For in it the righteousness of God is revealed from faith for faith,  as it is written, “The righteous shall live by faith.”(Romans 1:16-17 (ESV)
Not ashamed of the gospel.
Are you? There isn’t anything to be embarrassed about when it comes to the gospel. It is as Paul says the power of salvation to everyone who believes.
But not all believe. And those who don’t believe come up with many reasons to excuse their unbelief. Sometimes these excuses come in the form of mocking. Often believers aren’t knowledgeable enough to know what to do with the mocking of Jesus Christ and Christians. And then perhaps we don’t become embarrassed for the gospel but for our own lack of knowledge, our own lack of learning.
Of course, a person can always learn more concerning the gospel and the Christian faith. Apologetics can be extremely useful on occasion. Ultimately a person needs the gospel itself. When we know it ourselves it is then we can reveal it to others when they are ready to hear, use it to build one another up when we need building up. For when God reveals the gospel, it is not without effect. It is the power of salvation itself. A contagious power.