Heaven precludes genuine charity
If there is an omnipotent and perfectly just God and an everlasting reward, there is no reason to act morally except to secure one's own well-being in the afterlife, i.e. loving your brother can only be a rational means to one's own ends not the well-being of one's brother.
"Principle of 'Christian love': it insists upon being well paid in the end. [...] Ye want to be paid besides, ye virtuous ones! Ye want reward for virtue, and heaven for earth, and eternity for your to-day? [...] Ah! this is my sorrow: into the basis of things have reward and punishment been insinuated—and now even into the basis of your souls, ye virtuous ones!"
- If all else being equal my actions cause you to forego a good I have wronged you.
- Heaven is a good that outweighs all Earthly goods.
- In a perfectly just world, any wrong done to a person that can be compensated will be compensated.
- God desires a perfectly just world.
- God is omnipotent, therefore capable of compensating any wrong.
- If my actions caused you to forego Heaven (for example by convincing you to reject God or seeing that you die before repenting) you would be wronged. (Premises 1, 2)
- God desires to compensate any wrong. (Premises 3, 4)
- God would compensate you for that wrong. (Premise 5, Argument 2)
- No action of mine can deny you a good that makes all others trivial or otherwise affect your ultimate well-being. (Arguments 1, 3)
- No action of mine can deny you Heaven or otherwise affect your ultimate well-being. (Permise 2, Argument 4)
Therefore, my actions are irrelevant to your ultimate well-being (Argument 5) assuming a just God and an eternal reward (Premises 1-5).