Imagine a walk in the country side, ambling along, not quite sure which way to go but not aware of being lost. At a junction you see a sign post. How do you react to it? You can ignore it, dismiss it or follow one of its directions. The sign post can't show every possibility but it can highlight what is important. Also it can't make you go a certain way, you have that choice.
In Acts 26 Paul finally has a chance to address the king. However he chooses not to plead for his life but to tell his testimony. His desire is that everyone will hear about Jesus and believe (verse 29). He testifies to what God has done, and continues to do, in his life. He showed respect for his audience, and he did not apologise or dismiss his past, in fact he highlighted it as where he came from and he acknowledged God's part in it all.
Paul's testimony and witness of his life is the sign post to everyone he meets.
King Agrippa acknowledged that Paul was trying to persuade him to believe but he could not make that choice. He saw the sign post and chose to ignore it.
Are we ready to share our testimony in all circumstances and be a living sign post?