Heaven is not the final destiny of every human on earth. There is a hell. It is not a fictitious place.
Living the"good life," believing in "a god," but not The One True God, does not bring you to the place of eternal peace.
"Do not be deceived, God is not mocked; for whatever a man sows, that he will also reap." (Galatians 6:7)
If you do not have a life set apart
If you have not accepted God's free gift
If you do not believe in Him
If you do not live and walk as Jesus while you have the opportunity,
your eternal home is NOT heaven.
"For he who sows to his flesh will of the flesh reap corruption, but he who sows to the Spirit will of the Spirit reap everlasting life." (Galatians 6:8)
"And those who are Christ's have crucified the flesh with its passions and desires. If we live in the Spirit, let us also walk in the Spirit." (Galatians 5:24-25)