Facebook account blocked due to security

Hello,
I'm having the same problem.I forgot my password and I had to reset it but when I try putting my new password in it never works.what is go in on?Also its telling me I cannot get on facebook dew to security reason.what reason is that ??All I need is to be able to log into my account simple as that .I'm not a freaking hacker or anything I just need to get on my group page under my name Kim lewis.....email:***@*** the last password I used for this account were poohbear2012 please help me (Thank U)