The curse upon mankind will be removed - Revelation 22:3
And there shall be no more curse: but the throne of God and of the Lamb shall be in it; and his servants shall serve him:
In the New Jerusalem, all sin and the repercussions of it are removed. The curse that was placed upon all the earth and mankind will be gone – the earth will no longer produce thorns and thistles, men will no longer earn his bread by the sweat of his brow, women will no longer be doomed to bear the sufferings she does now, and mankind, in general, will no longer experience sickness, sorrow, tears, and death.