This passage does not teach that.
"He had no root in himself", this is born again? No root, so they just wither away.
In contrast, Peter describes the one who when they are tested, they are proven, because they are true.
This is someone "receives the word immediately with joy", but has no root. They have an emotional experience, but the Word does not penetrate to their heart.
In contrast to the first three grounds, the fourth alone is fruitful.
At least that's how I see this one.
Much love!
So, you believe that one is not born again until they endure for awhile to prove that he/she has root within themself?