Islam is based 1000 % on personal integrity. That means the credibility and believability of those who "Preach" Islam and "Practice" Islam.
Where our personal integrity is compromised, everything else becomes irrelevant.
In fact, Islam itself becomes a moot point.
After that, it does not really matter what else we do or don't do in this world.
Now, go and try to figure out if all this has any relevance to the fact that Allah prepared Muhammad, Sallallahu Alaihi wa Sallam, for years as As-Saadiq and as Al-Ameen before he sent him out in the world as Rasul and Nabiy.
Of course, As-Sadiq refers to integrity in speech, whereas Al-Ameen has to do with a person's integrity in conduct and character.