The best thing to do as a rule in life would be to "Believe" in yourself and very little in everything and everyone else.
But one should "Suspect" everything that exist around you to have some truth within it.
You have to undo all the programming that has been downloaded into your brain since birth and be as a child and use your own imagination.
The truth hides within the hidden part of your own creation of your reality. As the quest just might be about witnessing all these creations from the imagination of your own past memories, the present of your now in survival mode and the future of your dreams. As others who are constantly hammering you in to their reality also.
Maybe the journey is learn these lessons from your hidden remorse and your regrets along the way.
But alway try to remember once you "Believe" in someone or some idea those beliefs will close your mind to any and all other possibilities.
And in doing this you'll have committed not only your soul, but your hidden spirit as well, which your hidden spirit is like untouched clay of your imagination as you're always "in the now" shaping the clay of your spirit into your own reality that you imagined life to be.
To "Believe" is to end the quest.
To "Suspect" is to begin the quest.
Its best to keep an open mind and use common sense as your guide and stay on the quest here in this world as well as the next.