Thank you for your question.
Luke 8:5 A sower went out to sow his seed: and as he sowed, some fell by the way side; and it was trodden down, and the fowls of the air devoured it.
A man sows seed by scattering it upon his field. Some falls on the footpath at the side of the field, it is trodden on and birds eat the seed.
6 And some fell upon a rock; and as soon as it was sprung up, it withered away, because it lacked moisture.
Some seed falls on part of the field with rock just below the surface. When it germinates and puts down roots the rock prevents the roots reaching moist soil and the plant withers and dies.
7 And some fell among thorns; and the thorns sprang up with it, and choked it.
Some seed falls on part of the field which is full of thorns. The thorns being more vigorous in growth crowd out the plants and they die.
8 And other fell on good ground, and sprang up, and bare fruit an hundredfold. And when he had said these things, he cried, He that hath ears to hear, let him hear.
Some seed falls on part of the field with good soil; it germinates and grows to produce bountifully.
Jesus says let him that is willing to understand the meaning of the parable, understand it.
9 And his disciples asked him, saying, What might this parable be?
His disciples don’t know what the parable means so they ask him because they want to know.
10 And he said, Unto you it is given to know the mysteries of the kingdom of God: but to others in parables; that seeing they might not see, and hearing they might not understand.
Jesus tells them that they (the disciples) are to understand things related to the kingdom of God which are not readily understood. The latter are taught in parables which can be understand in the natural sense as a story told, but the spiritual lesson will escape those that have no inclination to serve God. Initially this refers to the hypocritical Jews of whom Jesus says elsewhere:
Matthew 13:14 And in them is fulfilled the prophecy of Esaias, which saith, By hearing ye shall hear, and shall not understand; and seeing ye shall see, and shall not perceive:
11 Now the parable is this: The seed is the word of God.
The seed scattered upon the field represents the word of God (in this case the gospel) preached among the people.
12 Those by the way side are they that hear; then cometh the devil, and taketh away the word out of their hearts, lest they should believe and be saved.
The foot path represents the people that hear but the ‘devil’ prevents it being lodged in their understanding so they cannot believe and be saved.
Those who suppose this devil to be the fallen angel of Christian mythology will believe that some unfortunates through no fault of their own are robbed of salvation by a supernatural being and God is happy to allow this.
Those who recognise the illogicality of this explanation will perhaps look at the parallel verse in Matthew where additional information is given.
Matthew 13:19 When any one heareth the word of the kingdom, and understandeth it not, then cometh the wicked one (literally ‘evil’ there is no ‘one’ in the Greek), and catcheth away that which was sown in his heart. This is he which received seed by the way side.
It is the inability to understand the gospel which results in the ‘devil’ or ‘evil’ removing it from his mind. If the ‘devil’ or ‘evil’ is in fact the propensity to sin which is resident in human beings because of our nature, then common sense triumphs.
The people represented by the footpath hear the gospel and do not initially understand it. They are not interested in pursuing it because they want to live their lives in their own (evil) way without God’s restraints.
Mark 7:21 For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders,
22 Thefts, covetousness, wickedness, deceit, lasciviousness, an evil eye, blasphemy, pride, foolishness:
23 All these evil things (same word as Matthew 13:19 there is no ‘things’ in the Greek) come from within, and defile the man.
In connection with the devil can I suggest you read this:
Do You Believe in a Devil? (Click the title)
13 They on the rock are they, which, when they hear, receive the word with joy; and these have no root, which for a while believe, and in time of temptation fall away.
The people represented by the thin layer of soil on a rock initially believe the gospel and receive it with joy, but when they encounter trials because of the gospel they cease to live by it.
14 And that which fell among thorns are they, which, when they have heard, go forth, and are choked with cares and riches and pleasures of this life, and bring no fruit to perfection.
The people represented by the soil among thorns initially believe the gospel but their ambitions and aspirations for wealth and pleasure in this life prevent them obeying the gospel in a way which is acceptable to God.
15 But that on the good ground are they, which in an honest and good heart, having heard the word, keep it, and bring forth fruit with patience.
The people represented by the good soil believe the gospel, obey it and live their lives in a way that is acceptable to God.
I hope this helps