noun
plural -liefs
a feeling of being sure that someone or something exists or that something is true [singular]
[singular] :a feeling that something is good, right, or valuable - + in
[singular] :a feeling of trust in the worth or ability of someone - + in
[count] :something that a person accepts as true or right :a strongly held opinion about something
[noncount] :the state of being accepted as true :the state of being believed
beyond belief
not capable of being believed
to the best of your belief
If you say something is to the best of your belief, you mean that it agrees with what you know and believe to be true.