Forgiving all or some sins

The Exalted has said: “Say: “O my Servants who have transgressed against their souls! Despair not of the Mercy of Allah: for Allah forgives all sins: for He is Oft-Forgiving, Most Merciful.” And the Exalted has said “O our people, hearken to the one who invites (you) to Allah, and believe in him: He will forgive you your sins, and deliver you from a Penalty Grievous.”

The first verse is counted to be forgiving all sins,and the second one only some of the sins,so how can we gather between the two?