Someone born (or baptised) into Hinduism and follows the Vedas, Puranas and the Bhagwat gita.
To the extent that following the tenets of those Vedas, Puranas and the Bhagwat gita is directly opposed to church doctrine, then only by the grace of God's mercy would such a person enter the kingdom.
well, quite frankly, there's no definition of a "true Hindu" -- at one level, everyone of Indian origin is a Hindu, by culture and thinking -- Hinduism doesn't confine itself to a bottle, you can have near athiests (arya samaj) as Hindus right up to near Christians who would believe everything that's Christian and may occasionally worship other deities.