信我的准没错 believe me,it won't be wrong

相信我 (xiāng xìn wǒ) --- trust me 真的 (zhēn de) --- It's true 我确定 (wǒ què dìng) --- I'm certain

相信我，没错的！

Well,In China,we have a phrase" 口说不如身逢 -- experiencing better than listening;耳闻不如目睹 -- seeing is believing".If you want to emphasize "believe it" cuz you saud,maybe PPL will doubts.i think you emphasize"you saud"better than "believe it". Would you pls help to correct my expression?

我发誓我说的都是真的。I swear my words are real.