The parable of the wheat and the tares forcibly teaches the lesson that salvation or damnation is not the result of a moment but is a process which takes place over a period of time. Unfortunately, the idea has become commonly accepted that a person may live a life of sin and at a moment of utmost extremity, call on the name of the Lord, and be saved by a mere profession of faith. But notice what Ellen White says.
"Those who are quieting a guilty conscience with the thought that they can change a course of evil when they choose, that they can trifle with the invitations of mercy, and yet be again and again impressed, take this course at their peril. They think that after casting all their influence on the side of the great rebel, in a moment of utmost extremity, when danger compasses them about, they will change leaders. But this is not so easily done. The experience, the education, the discipline of a life of sinful indulgence, has so thoroughly molded the character that they cannot then receive the image of Jesus. Had no light shone upon their pathway, the case would have been different. Mercy might interpose, and give them an opportunity to accept her overtures; but after light has been long rejected and despised, it will be finally withdrawn." Patriarchs and Prophets, 269 (See also Testimonies, vol. 1, 81, 82.)
Salvation is not obtained by a simple profession of faith. The faith that is professed must be perfected through a growth in grace. "In the Kingdom of God, position is not gained through favoritism. It is not earned, nor is it received through an arbitrary bestowal. It is the result of character. The crown and the throne are the tokens of a condition attained; they are tokens of self-conquest through our Lord Jesus Christ." Desire of Ages, 549 (See James 2:14-26.)
In the parable of the wheat and the tares, the wheat, or good seed, represents the gospel of truth. (See Signs of the Times, February 4, 1897.) When this seed is received, it begins to transform the character until the mind perfectly reflects the mind of Christ. (See Spirit of Prophecy, vol. 2, 244.)
As a person is what he thinks in his heart, the person who is transformed into the likeness of Christ, displays a Christlike character—a mature stalk of wheat.
Tares, on the other hand, represent the seeds of evil. Any seed of evil that is allowed to remain in the heart will eventually choke the good seed. "Even one wrong trait of character, one sinful desire, persistently cherished, will eventually neutralize all the power of the gospel." Steps to Christ, 34. As the seed of evil matures in the mind, it eventually becomes evident in a character that is symbolized by tares.
When the person is openly bearing evil fruit—living in open sin—he is to be disfellowshipped from the church but as long as he professes faith and is outwardly living according to the commandments, we are not to judge his character and motive. (See Christ’s Object Lessons, 71.)
Years ago we simply stated that the harvest is the end of the world, which is, of course, true. A careful reading of the parable, however, reveals something about the nature of the harvest.
All farmers know that the harvest is not instantaneous, but the closing period of the growing season. The same is true of the harvest of grace. Speaking of this event, Jesus said: "And in the time of the harvest." That phrase could also be accurately translated, "during the time of the harvest." The harvest time is that period in the "end of the age" of grace. It is that period of time when through the third angel’s message a final separation of the wheat and the tares takes place (see Early Writings, 118), when the character of every plant becomes evident and public.
Notice in the following quotation how clearly it is stated that the harvest is a period of time. "Let both grow together until the harvest. Then the Lord sends forth His reapers to gather out the tares, and binds them in bundles to burn, while the wheat is gathered into the heavenly garner. The time of the judgment is a most solemn period, when the Lord gathers His own from among the tares. Those who have been members of the same family are separated. A mark is placed upon the righteous." Special Testimonies, Series A, 6. Clearly the harvest is a period of time during which the character, which has long been developing through the growing season (the age of grace), is fully developed, and the destiny forever fixed.
Friend, do not be tempted to think that the harvest could not possibly take place without you knowing it. It could be over before you know it! (See Jeremiah 8:20; Early Writings, 71.)