In both Arminianism and Calvinism, the three Soils are Reprobate; but we differ on why they are Reprobate. A Traditionalist will eventually agree the Soils are Reprobate; Oneness will also eventually agree that the Rocky and Weedy Soils are given over to their Reprobate Minds...
Start with getting him to agree to this; then the rest of the things you want him to agree with will follow. Or else he will remain in Cognitive Dissonance and prefer the Lie...
@civic
In each case of soil type #2 and #3, they are living plants and therefore they are not reprobate (at least, for all practical purposes, as you look at them from the outside; or even from the inside, as one who believes he is eternally secure when in all actuality he will fall away or be choked out with the pleasures of this life) until it is shown that they are reprobate by virtue of the fact that they fall away or else are drawn away from faith in Christ by the pleasure that is offered to them by this world.
They are clearly not the elect; because they are a type of ground that cannot and will not sustain spiritual life permanently;
However, they are for all practical purposes what we might call "saved" (as we look at them in the church today, they are the parishioners who sit in the pews and who we greet every Sunday); since they are living plants for the time being and because they do exhibit spiritual life (while the difference with them is that they cannot bear fruit).
Only soil type #4 is the elect; and only soil type #4 can adequately lay hold of such promises as John 5:24 and John 10:27-30.
You can be certain that you are soil type #4 the moment you begin to bear real fruit (Galatians 5:22-23); because soil types #2 and #3, while they do exhibit spiritual life, cannot bear fruit.
The fact that they exhibit spiritual life means that, for all practical purposes, they are "saved" according to Acts 10:43; for, for example, soil type #2 "
believes for a while" and therefore can lay hold of the forgiveness afforded by that promise. However, because "
in time of trial or temptation they fall away", they are not forgiven eternally and therefore are not of the elect; they are forgiven only for a season in their lives.
I will not believe that a person who believes is not forgiven through their faith simply because they will not continue in that faith. Acts 10:43 is clear that believing procures forgiveness.
But if they don't persevere, the forgiveness that they enjoy will last only for a season.
That they have actual forgiveness is evident in the fact that they "
receive the word with joy". The joy that they experience is the result of being forgiven.