The essential qualification for belonging to God is not the good things we do, but the Saviour we trust.  False teachers have an amazing variety of wrong suggestions about how to get close to God, but Jesus said there is only one way: He is the way (John 14:6).  Everybody who believes in Him as the anointed Son of God, the Saviour of the world, is born into God's family as a much-loved child of God (John 1:12).  It is a blood relationship; we depend on the blood of Jesus Christ to atone for our sins and make us right with God (1 Peter 1:18-19).

Believing is not just an intellectual activity of accepting that facts are true; it is the willingness to place our confidence in Jesus alone to escort us through this life and welcome us into the eternity beyond.  Many accept that He is a great teacher and a humble example of unjust suffering; but they refuse to believe that He is God in the flesh or God's sacrifice for their sins.  According to the Bible, such people are not in God's family (John 3:18).

The test of which family you belong to is how you treat your brothers and sisters and obey your parents (1 John 3:23).  Belonging to the Father automatically puts us in relationship with spiritual siblings: loving them is evidence that we share God's fatherhood (1 John 3:10). But also, loving them is the evidence that we are glad to obey His commands.

It all starts with trusting Jesus.  The Bible says there is no other effective way to come to the Father; because without Jesus we are still in our sins and cannot even dare to approach God who is utterly holy. Our sins must be removed first … and that is what Jesus did in His role as the Christ.  Believing that gives us access to our heavenly Father and responsibility for His other children.  That is the challenge of the gospel; we enter God's family by believing that Jesus Christ is the only 'way in'.  Once we are born again, then serving our fellow believers is one of the first demonstrations of obedience which God looks for.