Best case
Spain wins both remaining matches. They finish on 13 points with a goal difference of +8. Even if the team in 1st also wins both, Spain is almost certain to advance as one of the top two.
Key idea: two wins usually locks in qualification unless the group is unusually tight.
Risky middle
Spain draws one and wins one. They finish on 11 points. The team in 3rd can still pass them if they win both and improve their goal difference. Spain would be watching the other match with fingers crossed.
Key idea: draws feel safe but can leave the door open for the team behind you.
Worst case
Spain loses both matches. They stay on 7 points. The teams below them only need one win each to overtake. Spain would be out unless both of those teams also drop points.
Key idea: two losses in a tight group usually means elimination.