Assalamualaikum... My friend talks to her male colleagues and goes out with them... and sometimes she put heart emoji when she replies to their posts on social media. The problem is, she thinks that it's not wrong because they're just friends. She's really good but i don't know why she's doing this! What should I do? Jazakum Allah khairan
Alaikumassalam wa rahmatullah,
That appears to be because of a lack of knowledge or piety. In general trying to make someone else a better believer leads only to negative results because you would be scheming to change someone’s state of mind which people find offensive, since they want to be free to reach their own conclusions. My advice is to never make someone your “project” where you try to improve them, that is a highly insulting attitude to have toward a fellow human.
Instead, attain a deep state of spirituality yourself (such as by spending an hour every night in tahajjud and Quarn-reading as I explain here). If you achieve such a state, your manners and character would probably do more to encourage her to become better than any argument. Al-Hasan al-Basri says:
Preach to others by your deeds, not by your words.
You could buy her beneficial books or encourage her to go with you to lectures. But you should not be attached to achieving any result. The best way to convince her to become better is to first become an admirable Muslim yourself, and second, to let her know through your words and actions that you love her for who she is rather than making your love for her conditional upon how well she lives up to your expectations.