Jesus tells the parable about the seed planted in the field. We have all heard the Gospel, we have all had the seed of the Word planted in our hearts, but we need to cooperate with God in helping that seed grow and bear fruit. In order for the seeds to grow, the soil needs to be tilled up, and suffering is what tills the soil of the soul. Also, there are weeds that need to be pulled, or they will crowd out the good work that God wants to do. Our sins and bad habits are the weeds that need to be pulled up.