For God so loved the world that he gave his one and only Son, that whoever believes in *him* shall not perish but have eternal life. [Author's emphasis]
John 3:16
AMP - 16 For God so greatly loved and dearly prized the world that He [even] gave up His only begotten (unique) Son, so that whoever believes in (trusts in, clings to, relies on) Him shall not perish (come to destruction, be lost) but have eternal (everlasting) life.
For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
The word him in John 3:16 is referring to The Christ, the Son of the living God. Christ said, I am the way, the truth and the life; for no one can see the Father expect believing on the Son first. Lord we believe that you are The Christ, the Son of the Living God and the strategy of the enemy is to keep us from believing but You left a Comforter; Holy Spirit enlighten our understanding that we may know and experience more of God's love daily.