I think it is fair to suggest that whatever your view of the end of this age and beginning of the next age (eschatology is the fancy word for this doctrine) is will determine how you both live and engage in mission in this age.
If for instance, you believe that the goal of mission is to “save souls for heaven” – then your primary and over-riding concern will mostly likely be proclamation. Telling people what they need to know in order to get them ready for heaven. This life will have one primary purpose to keep yourself for heaven and to tell others about it. Your church will probably have a sharp distinction between word ministry/ proclamation and social works. If you are really organised you might have a social work programme or two but you will spend large amounts of time making sure people know that you do not believe in the social gospel. But, at the end of the day, what really matters is getting people into heaven through hearing the gospel and making a decision for Jesus. You might even say this is all that matters.
If, on the other hand, you hold to an in-breaking Kingdom of God paradigm, then you will see the Kingdom as not only, or even primarily, a future reality but crucially as a very real present dynamic. Through the death and resurrection of Jesus God’s end time kingdom has now broken into this world in the middle of history. The Kingdom of God was not only announced in the gospel proclamation it was initiated in the life and mission of God’s people, the church. One day we will see the Kingdom come in all its fullness and glory when our King Jesus returns but now the Kingdom grow largely unseen, through weakness and on the margins of society.
Life among God’s people will be a small and incomplete foretaste of what that Kingdom will be like when Jesus returns. The people of God ought to be actively and intentionally living lives that embody that coming Kingdom. Lives of justice, mercy, grace, peace, beauty, restoration and joy. The old discussion of social justice versus gospel proclamation goes out the window within a Kingdom “initiated and yet not complete” paradigm. We are both to proclaim the arrival of the Kingdom (with the cross at the centre of that proclamation!) and live within the in-breaking Kingdom as those who experience the foretaste of the life of the kingdom and who long for the full wedding feast of the lamb.