a surprising symmetry

The following observation will likely get me in deep trouble with people of many beliefs, but...

You know how some pro-evolution proponents scoff at how some anti-evolution proponents point at comparatively minor differences or conflicts of evolutionary thought and say, "See? Even pro-evolution folks have serious doubts?" And the reason the pro-evolution proponents scoff at that rhetorical technique is because technical disagreements between experts don't change the fact that evolution is 1) widely accepted as the dominant viewpoint and 2) would need to exhibit much deeper problems to be overthrown as the dominant viewpoint.

You know how some Christians scoff at how some pro-homosexuality proponents point at comparatively minor differences or conflicts of theological thought and say, "See? Even Christian folks have serious doubts?" And the reason the Christians scoff at that rhetorical technique is because complex exegetical disagreements between experts don't change the fact that homosexuality is 1) consistently denounced as wrong throughout the Bible and 2) could only be considered as moral by bringing up much deeper inconsistencies (if sexuality, which is a huge part of being human, no longer has any restrictions, then was God kidding about that one commandment forbidding adultery?).

"an afterlife makes virtue mercenary"

Or, in other words, if religions (not just Christianity) promise rewards or punishments in the afterlife for deeds done now, doesn't that reduce good deeds to be "services rendered" in exchange for personal gain?

Sure, but only if a happier afterlife is the motivation for a good deed. In Christianity, no good deeds are sufficient for admission into heaven. It's true - Holy Harry, the upstanding community figure, can't cut it any more than anyone else. As Jesus told his listeners, they had to be more morally correct than their society's experts on moral correctness, the Pharisees and teachers of the law, in order to be part of the kingdom of heaven. The only way to make it in, is for the Christ to cover your unrighteousness with His perfection - known as "justification". Given that this is a central tenet of Christianity, no Christian (who knows what he or she is doing) should be consumed with concern for earning what is essentially a gift.

Does this mean Christians no longer need to care about what God thinks? Read some of Paul's epistles on the subject to convince yourself that forgiveness is not a "green light" for doing wrong (confession is vital, but the aim is to have progressively less to confess!). Again, this is an annoyingly common mistake. Sin is separation from God, meaning no fellowship with God. Hell is the soul's eternal separation from God. To put it frankly, the removal of sin is not just for You, that is, for your benefit. The sin is removed so people and the Holy God can come together. Someone who wants forgiveness for sin without pursuing a relationship with God is missing the point entirely! Not to mention that asking forgiveness is rather deceptive if you plan to go on doing what you asked forgiveness for. If you honestly, humbly desire to be a follower of God, you won't continue to do wrong, because that is the opposite of following God. Your moral compass has been corrected; why are you still going in the wrong direction, pray tell?

To repeat, hell is the soul's eternal separation from God. Heaven is then the soul's communion with God. The fact that God is good and the Source of all good things can make it seem like desiring communion with God (i.e., Heaven) is the same as desiring good things for you. Remember that according to the challenging book of Job, Job's trials are precisely to establish that Job honors God because Job's goal is to honor God, and not because Job wants God's blessings. So there is a difference. Someone who's making mental calculations like "if I do good deed C which costs me Q, I'll receive reward Z in the afterlife" has the wrong attitude. Just as people who correctly observe the root selfishness of that approach are not fooled, God is even less fooled.

A useful analogy is any act of sharing. People can contend for any resource, taking the whole by force, or they can agree to take a reasonable fraction and live peaceably, which is a better solution for everyone. Does the fact that sharing is a better solution for resource allocation imply that sharing is motivated by selfishness, out of the economic choice to certainly gain a little instead of risking injury and likely receiving nothing?

Coming to the point, the Good should be desired passionately, but such desire is not greed! Greed (or selfishness) is desire without limit. There can be no paradise for all if one individual refuses to appropriately curtail his own lusts. The believer should not overindulge, being mastered by addictions. But the believer should not overindulge in self-denial, believing that the highest ambition is to never be happy. Other belief systems may mention a Middle Way; Christianity's path is not so different in that respect.

Desiring to cultivate and experience the Good of harmonious moderation, and the ultimate of which is an afterlife with the Good God, is nothing to be ashamed of. Desiring to notch up points in the here-and-now in order to gain more for oneself in the hereafter, that is something to be ashamed of!

"There's no proof"

A favorite argument for atheism (agnosticism, antitheism, whatever) sounds similar to this: "I would believe in Deity X, but sadly there's no objective proof. When Deity X shows up, proclaiming its (the argument wouldn't use His or Her) existence with undeniable demonstrations, I will bow down to Deity X forthwith". This argument is particularly attractive to the same folks who tell you to replace religion with science. For them, the shorter version "your Deity doesn't fit in my test tube or appear in my telescope" is sufficient.

My point here is not to trot out specific proofs for or against God, but to show that someone who uses the above argument is engaging in creative deception. No proof is sufficient for them, who for the sake of convenience I will refer to as "no-proofers":

• The testimony of a witness or twenty is insufficient because a no-proofer can and will assert that the witness or twenty is unreliable/biased. What is the proof that the witness is unreliable? Because he claimed to see God, of course!
• A miracle or just a curiously providential coincidence is insufficient because a no-proofer can and will assert that the occurence was dumb luck or that it has an underlying natural cause (like a mirage) or that it's a piece of evidence that existing theories happen to not yet be broad enough to handle - such as explaining consciousness by theorizing that it somehow "emerges" from the multiplied actions of neurons.
  
• A no-proofer may assert that "Deity X" must not exist because a ritual didn't have the intended effect. But one cannot test the existence of a sentient being the way one might test the existence of charge in a battery. A sentient being must cooperate by responding, but for any number of reasons that being may elect not to. This is doubly true if the responding being is more intelligent and/or informed than the requesting being. To take a purely illustrative (not metaphorical) example, if person A phones person B, person B might refuse to say anything because person B is under surveillance that person A knows nothing about. A sentient being's lack of response doesn't imply that sentient being doesn't exist.
• In a deeper sense, even the "clouds breaking to reveal the face of God" isn't sufficient to convince some people that the apparition in question is Deity X. There's a principle often referred to as Occam's Razor which states that the less a statement assumes, the more likely it is to be true (because there's less for it to possibly be wrong about). Practically speaking, an omniscient/omnipotent/omnipresent God would almost never fit the Occam's Razor criterion for explaining anything. It's assuming a lot to state that any entity is just omniscient, or just omnipotent, or just omnipresent, not to mention stating that the entity is all three. Someone who's dogmatic about Occam's Razor would explain that the apparition in the clouds was some being with sufficient powers to move clouds and project a large image. No more, no less. One of the reasons Jesus' contemporaries kept accusing him of blasphemy is because according to Occam's Razor a blasphemous human is a far less assuming explanation than God Incarnated. So sooner or later, faith must be taken on faith. On the other hand, those who wish to consistently apply Occam's Razor can't admit the existence of a large class of intangibles; they're too busy trying to justify to themselves why Right is Right and Wrong is Wrong to work on the God question.
  
• No-proofers may comment that since others aren't believing based on proof, others are believing based on convenience. This comment has no bite for two reasons: first, beliefs that people hold to in the face of persecution/hardship/unpopularity hardly count as "convenient", and second, opposite beliefs can be convenient too. No God, no supernatural, no afterlife, all can sometimes be terribly convenient for no-proofers. They can think and do whatever they want. They can care about what they choose to. (Of course, conscience, responsibility, love, and duty won't be smothered or denied, so freedom isn't absolute even for no-proofers no matter how they try.)