Jesus is the Saviour of the world (1 John 4:14) and that He died on the cross for the sins of the world (1 John 2:2). This simply means salvation is available to everyone, not that everyone is saved. Only by the shedding of blood is remission, cleansing or forgiveness of sin (Heb 9:22, Mt 26:28, 1 John 1:7). Romans 3 states that righteousness (v.21) and remission of sin (v.25) are “by faith in Jesus Christ, unto all and upon all those who believe” (v.22) and “through faith in His blood” (v.25).
More to be written, come back later.
In the meantime please see this excellent article: http://www.biblebelievers.com/the_blood.html