Why is Adam (AS) at the lowest heaven and Abraham (AS) at the seventh?

OK so i finished reading the story of Isra and Mi'raj and when the Prophet got to the first heaven, he was greeted by Adam and then in the next by other prophets and so on untill the seventh heaven where there was Abrahm (AS). Is this the order that they will be in the hereafter or will they all be at the seventh heaven?