Based on the previous verses, there is a truth to evangelism that is important.  It is not about how persuasive we are or how gifted, but about the message.  The message of the cross is the power of the gospel.

Yes, your life is the apologetic.

Yes, we must do the best we can to present the message accurately and clearly and boldly.

But it is about the message of the cross.

So relax.  Share Jesus.