The early church father, Irenaeus, wrote the often-quoted phrase, "The glory of God is man fully alive." This smacks of pop-spirituality--best you, best life, right now. But there's truth in it.
God made us. He made us in His image; that is, to reflect His glory. God is glorified, therefore, when we live most fully in the way He made us. There's no glory to God in us being the worst versions of ourselves, denying His divine-hand on us, shirking what responsibilities are implicit in the gift of how we're made.
What does it mean, then, to be "fully alive"? This is answered in the never-quoted second part of the phrase: "The glory of God is man fully alive; and the life of man is in beholding God."
Again, we are images. Reflectors. We will be us, best, when we are situated in such a way that we see the Lord fully and may be seen by others fully. Like a good mirror.
So--pop-spirituality alert--to be the most fully alive you you can be requires a steady God-ward attentiveness. Contemplating Jesus and His relevance to your situation, as situation after situation comes to you.
And what is seen is not just Jesus, but us. That is, it is the most of the mirror that is seen and delighted in, when most of the mirror reflects the glorious image. Or, people really like a mirror when it shows them what they need to see, but can't, from where they're standing. Then it's a good, smart, truly-mirroring, mirror.
To be a good, smart, truly-alive, human, involves a closer attention to Jesus. It means listening to His Word. It means walking with His Spirit.
It is not found in any of the self-actualizing programs put forward by "SELF" or "FITNESS" or other glossy mags and sites. It won't be found in inward-gazing mindfulness. It won't be achieved when all the component parts of your body are working as you'd like.
No, it will only be enjoyed--by you and by others around you--when Jesus becomes more significant to us. And that is what the Father wants most. And that, as well, is what the world needs most. And that, lastly, is what it means to be truly alive.
"I have come that you may have life and have it abundantly." -Jesus (John 10:10)
Where does life come from? Jesus. How do we come alive? Depending on Him. And where does this process take us? To life that we were made for.