Spain have captured the imagination with their progress to the final, winning all their matches in some style. Compared with Germany, who have looked below-par on occasions but whose winning mentality has taken them through to another showpiece occasion, Spain look the team in form.
However, Alonso warned: "The best is yet to come and we need to finish off what we have done so far.
"We have to contain our happiness because we have yet to win the biggest game of all. We're hungry for success."
The Spaniards go into the final seeking their second major trophy - and first since 1964.
They look crtain to be without the tournament's top scorer, David
Villa, who has a thigh injury, but that hadn't knocked their confidence.
Arsenal midfielder Cesc Fabregas is expected tostart in Villa's place.
He set up two of Spain's goals in their 3-0 semi-final victory against
Russia, pulling in five-man midfield after coming on as a substitute
for the Valencia striker.
Fabregas said: "We have to respect Germany. They are a very strong and
very competitive team and are one of those teams that fight until the
end and it's going to be difficult to beat them.
"But we are united, all rowing in the same direction, and now we want
to give our fans the biggest joy of all, which is to take home the
Mark Hinton, Goal.com