'Evil' in the Bible

Take care, brethren, that there not be in any one of you an evil, unbelieving heart that falls away from the living God.

But solid food is for the mature, who because of practice have their senses trained to discern good and evil.

let us draw near with a sincere heart in full assurance of faith, having our hearts sprinkled clean from an evil conscience and our bodies washed with pure water.