Their teachings are not "contrary" to one another, but supportive.
Jesus says who will bear fruit, and John says who has born fruit unto God.
There is one, 1 John 3:9..."Whosoever is born of God doth not commit sin; for his seed remaineth in him: and he cannot sin, because he is born of God."BTW in the parable of the sower there are some important words about each "he" Jesus spoke about and that is that they "received seed." It is what they did with the seed after receiving it that was the problem that caused it to be stolen by the evil one. Show a scripture in John's "different situation" that indicates the seed of God cannot be stolen by the evil one. Correct, it isn't there.
Another is 2 Peter 1:10..."Wherefore the rather, brethren, give diligence to make your calling and election sure: for if ye do these things, ye shall never fall:"
And...""Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin.
For he that is dead is freed from sin.” (Rom. 6:6-7)
And..."Forasmuch then as Christ hath suffered for us in the flesh, arm yourselves likewise with the same mind: for he that hath suffered in the flesh hath ceased from sin;" (1 Peter 4:1)
And..."
“We know that whosoever is born of God sinneth not; but he that is begotten of God keepeth himself, and that wicked one toucheth him not.” (1 John 5:18)
He that is begotten of God keepeth himself...
He that is not begotten of God doesn't.
The parable of the sower is about who WILL bring forth fruit unto God.If you will understand 1 John chapter 3:1-10 you can receive light on this and see how it relates and supports exactly what Jesus taught in the parable of the sower and is in no way a "different situation" as you put it.
John's letter is about those that HAVE or have not brought forth fruit unto God.