The 27-year-old Real Madrid playmaker - who is yet to win top honours on the international stage - told uefa.com the Portuguese respected the Germans but they felt that they could cause an upset and quell fears back at home of an early exit.
"I don't like using that term 'revenge' in football, because it's simply a football match, it isn't a war," said Ronaldo, who first shone on the international stage as part of the side that lost to Greece in the Euro 2004 final.
"We want to win, which is obvious, because we want to start the European Championship well, and we know that Germany are a great team, they have had great results in recent competitions.
"So they're opponents who we respect a lot, but we also have our potential, we have our strengths, and we will do everything to start on the right foot."
Ronaldo, who was also in the side beaten by Germany in the largely meaningless third place match at the 2006 World Cup, said whilst they faced a tough task in the 'Group of Death' he was confident they would progress to the last eight.
The Portuguese, who have had a desperate run in to the tournament with a series of poor friendly results, have drawn not only Germany but also World Cup finalists Holland and 1992 title winners Denmark, who edged them in their qualifying group.
"We know that we are in the most difficult group of the European Championship, but it isn't anything to regret, because you can't change it, and we have known it for months," he told uefa.com.
"So therefore we have to be prepared. We don't have any other option - we have to face these countries, who are Germany, Denmark and the Netherlands. They will be extremely difficult matches, but I think Portugal will do a good job, and we will progress to the next phase."
Ronaldo, who had a stellar season with Real Madrid scoring 46 goals as they wrested the La Liga title away from bitter rivals Barcelona, denied being captain had had an adverse effect, though, he has to many peoples eyes rarely replicated his club form on the international stage.
"No (there is no extra pressure), because I have already been captain many times," he said.
"It can't put me under extra pressure, because it isn't an armband that will change my way of thinking. This squad is very easy to deal with, very friendly, very united, and so therefore it's easier to wear the captain's armband."
Ronaldo, who has said he would like to remain at Real Madrid for the rest of his career, also paid credit to coach Paulo Bento, who replaced Carlos Queiroz after they made a poor start in their qualifying group.
Bento, who will turn 43 on June 20 and will be the youngest coach at the finals, has been under fire of late but Ronaldo insists he has full confidence in the former international defender, whose last experience of a Euro saw him earn a long suspension for threatening the referee in the semi-final with France.
"I think that the coaches who make a mark are the ones with a personality, those who trust in their work, in what they have done, and trust in their team," said Ronaldo.
"He has a lot of trust in himself, in his team, in his players. He trusts them with his life, as it's said, and we also trust him because if the coach is good for us we also have to be good for him."