Try asking your friend to show proof of the transaction if they have sent Bitcoin to you, then does your friend answer it and provide the transaction ID. 
If not, then it is true what the friends who commented above have said, if you are being tricked. Remember 1 BTC is not a small amount, it's a huge amount so you have to be careful. 
Or maybe you can ask your close friend for help who knows more about crypto/Bitcoin, tell us the case you're experiencing and ask him for help to solve your problem.