I believe that the one true certainty is that of action. Before action decision must occur. Whether or not the action was correct will be observed later. But the possibility of "correctness" will only occur after action, thus influencing the accuracy of decision.
Most of us have learnt through trial and error. Unless you have a highly enlightened 'Guru' to guide you all along the path, mistakes may happen.
But as long as you remain true to yourself and Keep that Inner Fire Burning, you will eventually reach the Truth for Yourself.
I have come to the conclusion that the most important attribute one can have is the ability to unlearn all the wrong belief systems and behavior one has picked up, those rigid with their beliefs end up rejecting any radical truth they come across no matter how conclusive the proof is.
Try to inculcate a state of child like purity, curiosity, playfulness and innocence within you. A state where we love all and hate none, have no ill will towards anyone, not even our detractors and have a fresh approach to life with an eagerness to understand the wordly playground.
Whenever I have been in such a state, I have received answers to all my questions, cleared all my doubts and progressed rapidly.