When Jesus instructed His disciples to 'pray the Lord of the harvest to send out laborers into His harvest.', we realize that, in the historical context of the fullness of times, He was referencing that coming Day, when He would separate the sheep from the goats ( Matthew 25:31-46 ). That Great Harvest, though controversial, clearly pointed to the harvest 'at the end of this age' ( Matthew 13:40 )! Jesus, speaking to His first century disciples, still living under the rigors of that first age, revealed to them that they would be partakers of the first-fruits of the Harvest ( Matthew 24:31 )!
This is the Appointed Harvest of which we read in the pages of Scripture, that much should be clear! However, we should also understand that there is an Ongoing Harvest, of sorts, that is occurring while we speak. This Harvest, because of the infinite nature of 'the Lord of the harvest', is itself infinite, as the population of His Kingdom is infinitely increasing!
We are, in that sense, International Harvesters! The Body of Christ, Catholic ( universal ) is Harvesting for the Kingdom every day, as more & more of our Heavenly Father's sentient creation is returning to right relationship with Him! As His Ministers of Reconciliation, we ( corporately ) have entered into, not only the blessedness of that first Harvest, but that Eternal Harvest which will never end!
No one can successfully argue that, since that Harvest 'at the end of this age', all have been reconciled with their heavenly Father. This is a sad but glorious fact of life! Though we now live in that Blessed inheritance, there are still those who have not yet seen that Truth, as well as many who do not enjoy that Blessed Inheritance! When we reveal to those around us the blessedness of our inheritance & the Glory of Communion with our Heavenly Father, we show ourselves His fellow-laborers in that Eternal Harvest!
As previously, neither can anyone successfully argue that this is not Our Father's World! As David prophesied ( Psalm 2 ), our Father told His Son, 'Ask of Me, and I will give You the nations for Your inheritance, and the ends of the earth for Your possession'. Since we are the Body of His Son, we have, in that sense, inherited the earth, or His Kingdom! Though, as the apostle Paul wrote, 'I planted, Apollos watered, but God gave the increase' ( I Corinthians 3:6 ), it was those first century disciples, through the Power of the Holy Spirit, who were the workers in that Harvest!