What does John 3:16 teach about salvation?

John 3:16 encapsulates the core of the Christian Gospel by revealing that salvation is a gracious gift from God, given to those who believe in His Son, Jesus Christ. The verse emphasizes that this gift is available to 'whosoever believeth in him,' indicating that anyone, regardless of their past, can receive the promise of eternal life through faith. This doctrine underscores the importance of grace in salvation, asserting that human effort is not the basis of our salvation but God's love and initiative.