What is the ruling on marrying a girl who hates lying, when the suitor is a frequent liar, and she is unaware of that?

Lying is strictly forbidden and contradicts truthfulness, which is the foundation of faith. A believer cannot be a liar. Therefore, the questioner must repent sincerely, adhere to truthfulness, and abstain from lying, then complete his marriage to the girl, for his marriage contract is valid.