Impeccable
Impeccable , adjective
[Latin impeccabilis; pref. im- not + peccare to err, to sin: compare French impeccable.]
Not liable to sin; exempt from the possibility of doing wrong.
One who is impeccable; esp., one of a sect of Gnostic heretics who asserted their sinlessness.
God is infallible, impeccable, and absolutely perfect.