What? "Be alert and of sober mind" you have an enemy that prowls around.
Who? The Devil, also called The Serpent or Satan.
Why? Because he is looking "for someone to devour". His job description is to steal, kill and destroy.
Where? "Around." He has a pride (lion reference).
Interesting that the word "prowl" means to rove or go about stealthily, as in search of prey, something to steal and so forth, yet the "lion" or devil makes himself known with his boisterous voice.
The Holy Spirit has a Voice Recognition Package included when you accept His leadership of your life. I encourage you to always have this on and turned up to the maximum frequency. The devil might be saying the same kinds of things since the first day of The Fall of Creation, but Satan will always try to find a new and creative way to deceive you from the "weeds" or "bushes" where he is stalking you.
Sometimes believers are equated with sheep, some of the dumbest animals on the planet. But fear not, we have The Great Shepherd and He says about this awareness of the right or wrong voice - "My sheep listen to my voice; I know them, and they follow me." (John 10:27). I believe we are a special kind of sheep - God's Fold. And because believer's in Christ are in God's Flock they have God's Voice Recognition Package installed. So, "be alert and of sober mind" discerning the spirits (1 John 4:1-6).