The Bavarians, who lost the 2010 final to Inter Milan, take on Chelsea in their own Munich stadium on May 19.
"Our belief is greater than two years ago," the 28-year-old Lahm told a small group of reporters at the team's training ground on Thursday. "We are a group of players at the best football age.
"As a generation you are always measured according to titles and in Germany an international title is always necessary."
Sporting Bayern's red top and shorts, the softly-spoken Germany captain said defeats could be equally as important as victories.
"Defeats can prove positive. We lost the title two years ago and now we want it. We have that experience and that is invaluable," Lahm explained.
"We also eliminated a great team, Real Madrid, in the semi-finals this season. We have a better balance between offence and defence this year."
Lahm said Bayern, who have won the European Cup four times, had a slight advantage given they were playing at home.
"We can prepare in the same way as for any Champions League game," he said with a big smile. "Same hotel, same training, same changing room, the drive to the stadium although the atmosphere will be a bit different (with fewer Bayern fans)".
Each team will be allocated 17,500 tickets for the 66,000-seater Allianz Arena.
Bayern coach Jupp Heynckes, who also won the trophy with Real in 1998, warned his players not to be complacent.
"Maybe there is a slight advantage in our own stadium," said Heynckes. "But it will be a top team against us and so I think that it is about 50-50.
"I don't share the opinion that it will be easy or is already settled. We will not make that mistake and I have told my players that."
Midfielder Bastian Schweinsteiger also warned of Chelsea's desire to win the one trophy that has so far eluded them.
"Chelsea have played very well," said the midfielder while munching on some grapes.
"It also looks like this could be the last final for (veteran) players like Frank Lampard and Didier Drogba."
Bayern still have their last Bundesliga game at Cologne on Saturday and the German Cup final against Borussia Dortmund to play on May 12 but winger Arjen Robben said he was purely focused on the Champions League.
"The final is all I am thinking about," said the Dutch international who used to play for Chelsea, "a final against a team that have reached the semis six times in nine years.
"That 2010 defeat for us is a stimulus," added Robben who played for Chelsea from 2004-07 and declared that he still "loved" the London club.