Theism is literally childish

[John V]

You seem to be ignoring the fact that the Bible teaches that we get - or miss out on - eternal rewards based on our actions in this life.

I've always heard one could take a Mulligan on their death bed.  Did that rule change?

You don't understand the rules.

Salvation - yes, can be taken on the death bed. 

Rewards - nope, too late on the death bed. Person can still be saved as "one escaping through the flames," as Paul puts it. See 1 Cor 3.

Point is that, even if one believes in OSAS, there are still eternal rewards to motivate good behavior in this life.