In Mark 4:1-20, we find Jesus’ parable of the sower. As he begins, he says, “A sower went out to sow. And as he sowed, some seed fell along the path, and the birds came and devoured it. Other seed fell on rocky ground, where it did not have much soil, and immediately it sprang up, since it had no depth of soil. And when the sun rose it was scorched, and since it had no root, it withered away” (vv. 3-6).
Like Jesus’ original disciples, we probably have many questions as to what he means (V. 10). Thankfully, Jesus provides the answer in verses 14-19. As is obvious, I did not provide the entirety of the parable above, because I simply want to focus on Jesus’ explanation of the seed sown on rocky ground (vv. 16-17). First, let’s understand who the “sower” is and what’s being sown. Although not stated explicitly here, the “sower” most likely is Jesus, and what’s being sown is the word of the kingdom; that is, the word about the coming reign of Jesus the Messiah, the one sent to save his people from their sins (Matt. 1:21). While it is certainly true that Jesus is the “sower” mentioned here, it seems to me that as God’s people are sent out to proclaim the message of the kingdom (Matt. 28:18-20), every time we share the gospel with others, we are sowing the word as well.
As we sow the word of the gospel into peoples’ lives, a number of responses are possible. In Mark 4:14-20, Jesus explains the purpose of the parable he gave in verses 3-9. The purpose of his explanation is to provide clarity on the different ways people receive the word of the gospel. What strikes me about Jesus’ words are verses 16-17. Jesus says that as the gospel goes forth, some people hear it and “immediately receive it with joy” (V. 16). Sadly, this joy is short lived. Why? Jesus gives the answer: “. . . they have no root in themselves, but endure for a while; then, when tribulation or persecution arises on account of the word, immediately they fall away (V. 17).
Let verse 16 settle in your mind for a moment. These people heard the gospel and immediately received it with joy. They were ecstatic. They were overjoyed. They were thrilled. Maybe they even cried. The thought that they could be forgiven of their sins caused them to celebrate God’s goodness. To apply it to our own day, maybe they even joined a church. Maybe they got baptized. Maybe they served in the nursery, taught Sunday school, served as a deacon, etc. Regardless of how long they appeared to be believers . . . they weren’t. Oh, they may have cried when they claimed to be repenting of their sins, but it was all a sham (just like Esau [Heb. 12:17]).
What caused them to walk away? In context, Jesus specifically mentions persecution. A few verses later Jesus says others leave because “the cares of the world and . . . the desires for other things enter in and choke the word” (V. 19).
Why do I bring all this up? In J. I. Packer and Gary Parrett’s book Grounded in the Gospel, they talk about how most American churches are way too quick to allow people to enter and join their fellowships. Churches must learn to allow people to have time to simply sit in their pews, learn the ropes, and get to know people before immediately asking them to serve in some capacity. Since most churches are desperate to boost their numbers and give the appearance of growth, they oftentimes end up with unbelievers on their rolls. This is unhealthy and it reflects poorly on the church. While we certainly welcome unbelievers into our churches on Sunday morning, we do not want unbelievers to become members of our congregations. Such a scenario would lead to an unbeliever’s sinful behavior causing the church to have a poor reputation in the surrounding community.
Thus, while we long to see unbelievers come to faith, let’s also remember that time and truth go hand-in-hand. If someone says they’ve accepted Christ, let’s rejoice with them but also allow time to see the fruit of their repentance (Gal. 5:22-23).
 Walter W. Wessel, “Mark,” in The Expositor’s Bible Commentary, ed. Frank E. Gaebelin (Grand Rapids: Zondervan, 1984), 8:650.