|Plant seeds for the Gospel|
In Genesis 1, God repeatedly creates spaces (heavens, earth, and the seas) and then fills them with things. After creating each space and filling it, he declares that not it is "good" (tov in the Hebrew). In Genesis 1:27, when he has finished creation with the formation of Man in his own likeness and image, he describes it as exceedingly "tov". God also tells each species to "be fruitful and multiply" thereby filling the earth with even more "tov" things that reflect God's goodness, character, and glory. Each space is filled with good things that point to and reflect the character and nature of the only living God. These things are good, they are beautiful, and their reflection of God's goodness is an act of worship.
Then Genesis 3 happens. Eve looks ate the fruit of the tree and, after listening to the serpent, decides that it is "tov"/good. Instead of listening and trusting in the Word of God, she tries to redefine what is good and evil. Adam follows suit and sin enters the world through him and now, instead of the earth being filled with good things, the earth is filled with evil (the opposite of the original design). All of the descendants of Adam, instead of filling the earth with the image of God are now filling the earth with the image of someone whose very nature rebels against God.
Thousands of years later, God sends his Son to seek and save the lost. In dying on the Cross, he takes on the evil of the world and gives, to those who believe in him, the free gift of righteousness. Part of me supposes that if the New Testament were written in Hebrew, it would state that we have received the "tov" that comes by faith in Christ (Philippians 3:9). Christ redeemed us, made us new, and by His grace we are made good in the sight of God.
So how does this tie into the character of God? How does this relate to the things of God and missions? In redemption, God is once again filling the earth with things that are "tov"/good. And it isn't a "tov" that we've received from our own actions but one that comes directly from Christ and faith in his name. In sharing the gospel, in redeeming the lost, in proclaiming the glory of God, in enduring persecutions for the sake of the gospel, in standing strong for the truth of God, we get the chance to demonstrate to the world that this is the God we serve! We serve a God who chases after lost people. We serve a God who crossed the infinite gap between heaven and earth so that we could be reconciled to Him. We share the gospel because it fills the earth with the righteousness of God. We go on missions because there are places in this world that do not know of the grace of Christ. If we're going to emulate the person of Christ we must be about his business. We can't ignore this aspect of his character. In short, we're missional because the God we serve is missional.
God chose to use us to proclaim his glory to those who don't know Him, both near and far. To quote David Platt: "We are plan A, and there is no plan B..."