James wanted his readers to look forward. We see this future emphasis in his use of the word ‘firstfruits’, which was taken from the sacrificial rituals in Israel in which a sample crop was offered to God in anticipation of the coming harvest. James' illustration points to two facts.
First, those early Christians, who are the sample in this illustration, have been dedicated to God. This is what they would have done at their conversions and James is encouraging them to continue in a state of dedication despite the difficulties they were facing. Since they were dedicated to God, they were his possession and belonged to him. James is saying that they were no longer their own.
Second, what does James mean by 'creatures' here? There are two options. One is that his readers are the sample that depicts the coming harvest of believers. This might have seemed very unlikely to them in their sufferings. Their circumstances might have said to them that they would be the last of the Christians rather than the first. In this explanation of the meaning of ‘creatures’, those suffering believers were the guarantee that there will be many believers in Christ throughout the coming centuries.
The other option is that the sample refers to all believers (with the readers being part of it), and they will be followed by the recovery of other creatures to God’s kingdom in the future, in the new heavens and new earth. If this is the meaning, then James is telling his readers, who are living difficult lives in a very troubled world, that they are part of the guarantee of a better world in which the whole of creation will be restored.
I don’t see why both options cannot be true. There is a great future ahead, promised by God, of which those believers were the visible guarantee that it would come, even when they were undergoing persecution for the faith. This future includes the certainty of believers coming to faith down the centuries as well as the perfect world of glory after the resurrection.
What are believers undergoing persecution to think about? The glory ahead, and which is nearer than ever before. What are believers not undergoing persecution to think about? The glory ahead, and which is nearer than ever before.