I am worried because all my friends have full facial hair and all I have is like bumfluff hairs. Is there something wrong with my genes? My dad's grew the thickest beards you could imagine.
What is missing is how far you've developed. Most men aren't able to grow a full beard until they reach their mid-twenties. Your friends may have merely developed earlier than you or have darker facial hair which is more noticeable even if it is thin. The answer for most young men is to be patient and give yourself time to mature.
"Nor shall you swear by your head, because you cannot make one hair white or black" (Matthew 5:36).