God offers salvation to everyone, but only few will accept. We, who are His, know that He is always with us. God's Word says in Psalm 4:3, "Know that the Lord has set apart the godly for Himself; the Lord will hear when I call to Him." People in a close relationship know each other’s voice no matter if it’s a child’s or an adult.
Jesus, the Good Shepherd, reminds us that even animals (sheep) know the voice of one who cares, protects, and loves them. May we always obey that voice and know He always hears ours.