diffident
shy; not assertive
fidelity
faithfulness; loyalty
confide
to trust (another) with information or a secret
fallacy
a misleading or mistaken idea
fallacious
misleading or deceptive
fallible
capable of being mistaken; imperfect
credible
able to be trusted in or believed
credence
a trust or belief
credulity
a tendency to believe things too quickly or easily
incredulous
unable to believe something; amazed
dubious
uncertain; doubtful
indubitable
certain beyond doubt or question
redoubtable
worth of fear or respect; mighty