The world, in biblical terms, is humanity against God. The word sinner in the NT is the individual against God. So Christians may commit sin, Gal 6.1; Jas 3.2; 1 Jn 2.1, but are not sinners, in this sense. The NT does not call the saints of God sinners, for they have stopped practicing sin.
Let us be careful that we do not, by the use of such statements as, “We’re all sinners,” justify the practice of sin and adjust ourselves to a tepid faith that accepts the lack of holiness among us, without which no one will see the Lord, Hb 12.14.