How can you tell whos lying to you?

Ok.....this is weird! I just hapd a party in my last class and were all chilling and having a good time. And this one girl who i kinda know said she wanted to hear me sing again. And im like " again?" and she said i was in chorus with her last year and she sat behind me. She said i have a voice like an angle......but im thinking shes thinking of my friend who sat next to me Andriana. She has a really fabolus voice! So when i said that she said she did, but then went back to my voice. SO she wanted me to sing a bit to her. She wanted me to sing a bit of HillSong for her. So i did so, i sang to her my new song and she just loves my voice. SO im singing on the way to 7th period and i go up to my best friend and she told me to stop singing. So I asked her why and she said i cant sing. Now i have never been told i had a really good voice...so that was new to me. BUt my best friend told me that i cant sing. Now why would my best friend lie to me about that, but someone who i barley know would want me to sing to her. How can I tell who is lying to me? Cause now im having mixed.......well.....you know. Im not sure if the other girl was trying to make fun of me or if my best friend just hates the fact i can sing. IDK! But I dont know myself. Ive recorded myself before and i think its like 50/50. Or is it the way people hear my voice? Who knows? But i know that the one thing that will never change, is singing for my maker....the Lord Jesus! He is worthy of my praiseand i will sing to HIm rather people tell me i sing good or that i break windows!