Incorrect happy A, Giving yourself meaning, is STILL meaningless, for you, I disagree, with Objective meaning, Who are you to state this? The meaning and purpose of life isn’t all that easy to figure out. To answer the question involves answering other questions: What does it mean to have meaning and purpose? How do you determine what that is? Do you determine your own meaning? Can you combine what you think is your own purpose with the purpose that someone else might have for you? There are lots of questions and no easy answers. Well, let me correct myself. There is an easy answer.
There are those who will not like this. There are those who will deny that God has made us. For them, they want to determine their own purpose. They must decide for themselves what is meaningful to them. They want their independence. They want to proclaim what is good and bad in their own hearts and determine their purpose based on their desires. But the problem is that this becomes self-serving. When we do what we think is right in our own eyes, we often make mistakes--especially when we deny God. When a child says, "I want, I want, I want," he is showing his immaturity and self-centeredness. Adults become other-centered as is demonstrated by the sacrifices involved in parenthood and marriage. As we grow older, we realize the value in considering the interests of others. "Do not merely look out for your own personal interests, but also for the interests of others," (Phil. 2:4). In this, we learn that purpose is best defined not by selfish desires but by the ability to love and consider others more important. This carries over to receiving a purpose from God. If we are selfish and want to determine our own purpose, then how is that truly loving? After all, if love is other-centered, then shouldn't we love God, center our lives on Him, and humble ourselves before Him in His wisdom and trust what He desires for us? Think about it. He knows infinitely more than we do; and by trusting Him, we can discover the ultimate purpose of our lives. It makes sense.
As for atheism? Sheesh, In discussions with atheists, I don't hear any evidence for the validity of atheism. There are no "proofs" that God does not exist in atheist circles, at least, none that I have heard, especially since you can't prove a negative regarding the existence of God. Of course, that isn't to say that atheists haven't attempted to offer some proofs that God does not exist. But their attempted proofs are invariably insufficient. After all, how do you prove there is no God in the universe? How do you prove that in all places and all times there is no God? You can't. Besides, if there was proof of God's non-existence, then atheists would be continually using it. But we don't hear of any such commonly held proof supporting atheism or denying the existence of God. The atheist position is very difficult, if not impossible, to prove since it is an attempt to prove a negative. Therefore, since there are no proofs for atheism's truth and there are no proofs that there is no God, the atheist must hold his position by faith.
Faith, however, is not something atheists like to claim as the basis of adhering to atheism. Therefore, atheists must go on the attack and negate any evidences presented for God's existence in order to give intellectual credence to their position. If they can create an evidential vacuum in which no theistic argument can survive, their position can be seen as more intellectually viable. It is in the negation of theistic proofs and evidences that atheism brings its self-justification to self-proclaimed life.
There is, however, only one way that atheism is intellectually defensible and that is in the abstract realm of simple possibility. In other words, the atheist would have to propose that it may be possible that there is no God.1 But stating that something is possible doesn't mean that it is a reality or that it is wise to adopt the position. If I said that it is possible that there is an ice cream factory on Jupiter, does that make it intellectually defensible or a position worth adopting merely because it is a possibility? Not at all. Simply claiming a possibility based on nothing more than it being a possible option--no matter how remote--is not sufficient grounds for atheists to claim viability in their atheism. They must come up with more than "It is possible," or "There is no evidence for God," otherwise, there really must be an ice cream factory on Jupiter, and the atheist should step up on the band wagon and start defending the position that Jupiterian ice cream exists.
At least we Christians have evidences for God's existence, such as fulfilled Biblical prophecy, Jesus' resurrection, the Transcendental Argument, the entropy problem, etc.
There is another problem for atheists. Refuting evidences for the existence of God does not prove atheism true anymore than refuting an eyewitness testimony of a marriage denies the reality of the marriage. Since atheism cannot be proven and since disproving evidences for God does not prove there is no God, atheists have a position that is intellectually indefensible. At best, atheists can only say there are no convincing evidences for God that have been presented so far. They cannot say there are no evidences for God because the atheist cannot know all evidences that possibly exist in the world. At best, the atheist can only say that the evidence presented so far has been insufficient. This logically means that there could be evidences presented in the future that will suffice. The atheist must acknowledge that there may indeed be a proof that has been undiscovered and that the existence of God is possible. This would make the atheist more of an agnostic since at best the atheist can only be skeptical of God's existence.
This is why atheists need to attack Christianity. It is because Christianity makes very high claims concerning God's existence, which challenges their atheism and pokes holes in their vacuum. They like the vacuum. They like having the universe with only one god in it: themselves.