My Almighty VS your argument against it

[Belacqua]

Meaning is such an ambiguous word that it's difficult to know what someone really means when they say it.

This was my reaction, too. What does the word "meaning" refer to here?

Off the top of my head (and I'm pretty sleepy) meaning can mean:

1) conveyed information: "The sentence is garbled; its meaning is unclear."

2) devotion to a practice: "My meaning in life comes from my baseball card collection; I work on it every day."

3) influence: "The attempt was well-intended, but made no difference. In the end it was meaningless." 

4) significance: "Her gesture turned out to be quite meaningful, in that it made people aware of the issue." 

5) importance: "A job at the car dealership is meaningless; better to be a doctor and have a meaningful role." 

Christians think that, since God has written the world like a book, with us as characters, life can have meaning in the first sense, above. Our lives (like all objects or events) refer to something and convey a message which the wise can interpret.

I suspect that the assertion "I give my life my own meaning" refers to the second sense. It's saying that one decides for oneself what one is devoted to, whether this is culturally significant (doctor) or not (anime obsessive). If someone assumes that we have a moral imperative to use our lives for good, then he may judge that our chosen meaning (say, anime obsessive) is meaningless. That is, the meaning (devoted practice) that we have is pointless (meaningless). This may be an objection that a Christian would make against the atheist's claim that one creates one's own meaning -- your meaning might be trivial, thus, in fact, meaningless. 

3 - 5 are pretty similar, and are probably more what people mean when they say life without God would be meaningless. They think that if we all just live and then die and are forgotten, then all of our acts don't register in any permanent, transcendental way. Even the hero who saves a hundred lives -- what's the point, since all those people he saved are just going to die later anyway. 

Probably we want to be wary of sidestepping from 3-5 over to 2. "Your chosen life is meaningless!" is an accusation concerning 3- 5. "No it isn't; I've devoted myself to exactly what I enjoy most" is a reply based on 2.