'Mortal' in the Bible

‘Can [mortal] man be just before God or be more righteous than He?Can a man be pure before his Maker or be more cleansed than He?

“Yes, I know it is true.But how can a mortal man be right before God?

“Behold, I will not make you afraid or terrified of me [for I am only mortal and not God],Nor should any pressure from me weigh heavily upon you.