This is my take on Mission. It starts with worldview.
There are two worldviews according to the Bible: Belief in the true God or belief in false gods. For those who refuse to worship and submit to God, they have, knowingly or unknowingly, created their own god. Even those who haven't heard the Gospel are accountable according to Paul (Romans 1:20). To summarize, every human worships something. Religious people worship false gods and people who reject religion make themselves god. I did not create this concept, it's been plainly stated for centuries in different forms. But it is important to differentiate those who follow Jesus as God and those who do not. If you profess to be a Christ-Follower and believe the Bible, then you submit to God as your highest authority and His Word as true and infallible.
As Christ-Followers, what is our purpose? The Bible makes it clear that God created man and that He created him for His glory. Therefore, the ultimate purpose of man, according to the Bible, is simply to glorify God.
We fulfill our purpose of glorifying God by living our lives in faithful service to Him (1 Samuel 12:24 John 17:4). Since God created us in His image, our purpose cannot be fulfilled apart from Him. King Solomon concluded that the only worthwhile life is one of honor and obedience to God (Ecclesiastes 12:13–14).
Jesus told his followers their Mission - To make disciples of all nations. That includes both in words and actions.
Actions: Matt 5:16 says to let your light shine before men so they may see your good works and glorify your Father which is in heaven.
Words: Mark 16:15 Go into all the world and preach the gospel to all creation.
This Mission, by default, is huge and unreachable. That's key because men often choose a mission that is too easily achievable, and the satisfaction that comes from easily achievable goals is fleeting. Think of the greatest thing you've accomplished in your life. Does it sustain you still to this day? Can you honestly say that this massive goal you accomplished gives you an ongoing sense of fulfillment? I bet you would say it does not. In fact, I would argue that achieving the goal was not as fulfilling as the journey to complete the goal. The mission to make disciples is a lifelong, never-ending goal that we know will never be completed. This means that we can continue pursuing this mission until we die. Along the way we may see great success bearing fruit, but the key here again is that we will always have the mission to pursue and therefore something to strive for and a place to exert our energy. This fulfills our purpose to glorify God through following His commands and it creates legacy. Legacy is the effect of our actions after we are gone. As we make disciples, we are expanding the Kingdom of Heaven. We are removing souls from eternal wrath away from God and adding souls to eternal peace with God. What better legacy can a man leave? When God asks me, "What did you do with your time on earth?" I need to be accountable for my actions. I need to store up treasure in heaven.
Because the Mission is so big (and important), we shouldn't arrange the Mission around our lifestyle, we should fit our lifestyle around the Mission. See Francis Chan quote below.
If we are believers and disciples of Christ, we turn our focus to the external world to make disciples. But what about existing believers? Is that part of the mission? Of course! We are to serve one another using our gifts and talents (1 Peter 4:10). The definition of humility is not to think less of yourself but to think more of others. Isn't that the essence of serving? Cynical people may suggest that serving others is validation seeking. If that were so then the Apostles were constantly seeking validation! But it is a point that needs addressing. The Pharisees were religious people who did the right thing with the wrong motives so it's entirely possible that you could be serving people out of a selfish desire for validation. But Paul's writings exhort believers to support and serve others so let's add this to our Mission.
Every Man's Outwardly Focused Mission
Every Christian Man's Mission is to be outwardly focused on making disciples and serving others. This includes through both words and actions. John The Baptist was "the voice of one crying in the wilderness" and Paul boldly proclaimed the Good News of Jesus Christ everywhere including synagogues, marketplaces and even prisons. We should follow Paul's example of spreading the Gospel with words and actions.
My family are full-time missionaries to our local community of around 50,000 people. When we mention we are missionaries, church friends often respond, "We let our lives point to Jesus," which would be great if it worked. But I don't see it producing fruit. It sounds good, but rarely is lifestyle alone effective. At some point you have to outright explain the Gospel. Be careful however because we are commanded to proclaim not persuade. Persuading is the job of the Holy Spirit (John 16) and He does it better than you ever could.
Jesus traveled from town to town telling men to follow him and intentionally teaching large crowds. The book of Acts is an entire book about preaching and proclaiming the gospel.
But to those who don't often proclaim the gospel, this is just as important as letting your lifestyle point towards Christ.
Francis Chan wrote a free book called "You and Me Forever" which talks about our mission in life. Here's my favorite quote:
Command: Make Disciples. This command should dictate everything about your life: Where you live, where you work, where you spend your money, how you spend your time - EVERYTHING! You should not make a single decision without the words 'Make Disciples' factoring in. We should be constantly asking ourselves the question: How can we free up more time and resources for making disciples.
For the sake of your eyes, I removed about 50% out of this post and condensed it to a few main points. As I was re-reading the sidebar content on Mission it struck me that discussion about Mission isn't what is lacking in this sub, what's lacking is action. I encourage each of you to post in OYS and create opportunities to make disciples.