The Lord's parable of the seed (Lk 8.4-15) is chiefly about the Father's reckless spreading of His Word (Logos) which is carried aloft by the pneumatic wind. However, one cannot discount the metaphor of the four soils which Our Lord also employs in telling the story. When one considers the soils, it is not uncommon for the heart to be pricked and to ask, "How do I keep myself from becoming thorny, rocky or hard ground"?
According to the fathers, the making of good soil and the bearing of fruit is a cooperative effort intiated by the Holy Spirit, who both carries the seed/word to all soils and also begins the work of preparing the soil.
Yet we also have a part; namely, the life of repentance. Should we depart from constant repentance, we can quickly revert to thorny soil (being caught up with this world's false promises), rocky soil (consenting to faith intellectually but not in spirit) and finally to hard ground (where God's word matters little to us, and we matter most).
The life of repentance, which is our part, is aided by prayer, fasting and almsgiving--as the season of Lent teaches us. St Augustine says it another way in the form of a prayer: "Teach me, Lord, to see You so that I might love you truly, and to see myself so that I might cease loving myself."
To strengthen us in this life of self-denial, God's grace is necessary as He proffers it and pours it upon us generously by the Spirit in the sacred mysteries, most particularly Private Confession and Holy Communion.