What does it mean to be Man Fully Alive?

Saint Irenaeus, who created the saying

The first order of business is analyzing the sentence grammatically. The question that arises is whether Man Fully alive describes the Glory of God, or the other way around. Because this question can only be answered by personal opinion, we'll just show the meaning of both and say they're both true.

Let's begin with the original saying. The Glory of God is Man Fully Alive. This sentence is a simple sentence. No commas. Only one clause. Yet, it has an incredible amount of meaning. The surface of this quote seems to say that God's awesomeness is only when man is fully alive. That's false. Remember, God is perfect. Nothing can make him better. So let's draw a distinction between glory and awesomeness. Being awesome is when you're awesome. Glory is when you're awesome and people see it. Glory is when a pro baseball player hits a home run in the finals of the World Series. Awesomeness is when he does that same hit during practice. So God's glory is something we see. From here, I think the conclusion is that Man Fully Alive is what allows us to see God's glory. So let's discuss what God's glory is. God created mankind to be with him, meaning we are supposed to follow his calling. All that we do ought to be given up to God. Otherwise, we would be violating our purpose of existing. As such, we must do what we can to witness God. So that means we need to listen to that internal voice to be with God.
So what is God's message to us? Well, this comes in many forms. The first is pretty subjective. THe most obvious way God speaks to us is through some kind of vocation. While we can verify that God calls everyone to follow a career path or act in a certain way, there isn't some definite example of God's call to us, as everyone is called to do something different. The second way, the more important way, we are called by God is to love others. As Christ said, we should "Love others as I have loved You." What makes love such a central part of what it means to be Catholic? Well, we're all equal. God made us to be in union with him, meaning we all have an equal "dose" of humanity. This means we can't just arbitrarily assign what it means to be human. All people are different. That's what makes us similar. In that way, God calls us to love others as we lover ourselves, because others have the same human dignity and moral worth as we do.
So now let's go further and analyze why being fully alive means accepting the Glory of God. Man was created by God for one reason: to be in his presence. This means that in order to truly be happy, to be true to our essence, we've gotta be with God. This is where the saying really culminates in a simpler meaning. In order to be fully alive, in order to fulfill our purpose, in order to be happy, we have to be with God. God's glory is the only thing that makes us happy. That means we must do thigs for God's glory and not our own. We shouldn't have the idea that everything we do is for us. We should do things for God. That also means doing things for others. Since, again, God created us equal, we have to respect that and follow that. Honoring God and God's will means helping others, bringing glory to them and not ourselves. So, to sum it up, being man fully alive, acheiving the Glory of God, is treating others as God treats us in order to respect him as we respect ourselves.