You probably faced someone already who told you that some parts of the Bible were fake...
Some scholars will say that, but with fancier words... and one of their likely tarted will be 1 Timothy, 2nd Timothy and Titus (known as the Pastoral Epistles).
I read something interesting that I stumbled upon by chance today, a websie dedicated to their study. Its author has a blog and brings some interesting arguments against the claim of stylistic difference between the unanimously agreed Pauline corpus and the Pastorals. Warning: I didn't double-check his facts though.
So, there you go Rumors of Pseudonymity Greatly Exaggerated