Am I sinful if a young man who is not religiously committed admires me? And what should I do if he proposes to me? And should I agree to marry him despite his lack of religious commitment?

No one is held accountable for the sins of another; every person is responsible for their own actions. No sin accrues to a woman who is looked at if she adheres to the hijab (definition) and avoids forbidden mixing. Attention should be directed towards matters of religion and worldly life. If a young man proposes marriage, there is no harm in accepting him as a husband if he is pleasing in religion and character, observes his obligatory duties, and does not commit major sins. Otherwise, he should not be accepted.