Why does grace + law(addead) end as bad as blessed + cursed = accursed, and as bad as life + death = dead end?

Is that why James says sweet (grace) + bitter (law) ought not come out the same mouth, and should not be given any amen if any of many coming to deceive (law) say such earthy, sensual, devilish wisdom which is not pure wisdom (grace) from above, nor peaceable, nor gentle, not easy to intreat, nor full of mercy, nor full of good fruit, nor without partiality, nor without hypocrisy?