The parable explained Matthew 13:36-43
The clear meaning - Jesus, the son of man has "sowed" His children throughout the word. The enemy (Satan) as corrupted the field and mingled his children with God's children. Together, believers and unbelievers live side by side. The final Judgement, GOD, not man, will separate the wheat (believers) from the tares (unbelievers).
The field is not the Church - it is the world. The UN-biblical notion that we in the body of Christ (the church) are to permit and tolerate unbelievers is False. Nor should there be any notion that this parable some how illustrates that believers in the church have some sort of divine permission (in the name of love, unity, or tolerance) to let them be - thinking that eventually God and His angels will sort them out.
Quite the contrary - Believers in the church are to have nothing to do with false teachers and those who corrupt other believers. 2 John 9-11 Anyone who goes too far and does not abide in the teaching of Christ, does not have God; the one one who abides in the teaching, he has both the Father and the Son. If anyone comes to you and does not bring this teaching, do not receive him into your house, and do not give him a greeting; for the one who gives him a greeting participates in his evil deeds (NASB).
Indeed, we are commanded to - 1 Corinthians 5:7 Clean out the old leaven so that you may be a new lump, just as you are in fact unleavened. For Christ our Passover also has been sacrificed (NASB).
This parable is instructions for the church living in the world. We live, breath, and share the world with unbelievers, but we are not to rid the world of unbelievers. Historically we have ample examples of when the church does not heed these instructions; the Inquisition and other early church history of fanatics killing genuine believers thinking they are the enemy.
The church's mission is not political - believers are not called to "destroy" anything. God has planted us in the field (the world) for a reason; attempting to escape that fact is useless, in other words you'll bear no fruit. You are where you are today to bring God glory, not escape from the world.
Let us also consider the symbolism at play here. Genuine Tares can never be Wheat. However, a "son of disobedience" can be transformed. Paul reminds us we are all by nature children of wrath (Ephesians 2:2-3). Our Faith (our salvation by God's grace alone) transforms us into "God's household" - verse 19 So then you are no longer strangers and aliens, but you are fellow citizens with the saints, and are of God's household.
In essence, from our fallen nature in Adam, all wheat begins as tares, no? Without the divine breath of Christ - this transformation will not be a reality.
Make no mistake, sons of the evil one may masquerade as sons of God. How will the "reapers" know who is which? Pay close attention - verse 41 The Son of Man will send forth His angels, and they will gather out of His Kingdom all stumbling blocks, and those who commit lawlessness.
Clearly the difference lies in behavior and character - one might call these things "fruit". A tare bears no fruit, wheat does. In the final judgement - the reapers will assuredly know. Believers need not force the Kingdom of God unto the world. We need not "throw pearls before swine" - we are commanded to teach and preach the gospel, and live a life that bears fruit with mercy and grace. A "solider" of Christ does not write his own orders, he obeys the orders he as been given.
The question may arise, if someone says they're a Christian, shouldn't we just believe them and take their word for it?
No. The body of Christ is to always be on the look out for wolves in sheep's clothing. Liberal theologians have taken this "tension" and broke it down to nothing less than utter indifference to sin and ungodliness. Remember, the text here reminds us about the difficulty in telling wheat from tares, not that there is no difference!
An equally important point that can be illustrated from this parable for the believer - is acknowledging the fact that the ungodly do indeed often appear to be righteous. So we have both a warning and a the command - let them grow together in the world.
Thus we must preach and teach against sin. Guess what, we might just have a positive effect on some tares. It may seem like a really foreign concept today, but Christians are not suppose to live and behave like unbelievers. Repentance, a call for holiness, and submitting to the Lordship of Christ and the authority of His word are not optional.
In the end, the crop will be clearly identified and in the hands of God and His angels. A good tree cannot produce bad fruit, nor can a bad tree produce good fruit (Matthew 7:18). If the fastest growing denominations are the ones consisting of practicing homosexuals, as evidenced in our recent times, then these are not sons of God, but clearly sons of the devil - indeed you will know all of them by their fruits.
Live with righteousness, teach against sin and it consequences, and be living examples of a holy life lived in sacrifice to God. We are not God's reapers - we are sons of the living God, maturing in our faith - ever aware of the false teachers and swine we live together with. The church never offers a free for-all pass into its fellowship (2 Corinthians chapter 6); nor should it "command fire to come down from heaven and consume them" - Luke 9:54, albeit we may understandably desire instant judgement and retribution against the wickedness in the world.
Living under the Lordship of Christ; teaching and preaching the Gospel - is the difference between wheat and tares. A superficial response to the Gospel is a clear sign you remain a tare, in the ever growing epidemic of false professions of faith in Christ. Disobedience is nothing less than unbelief, plain and simple.
It's only a matter of time before the harvest. Repent, carefully count the cost, and follow Christ!
1 Peter 5:10-11
10 After you have suffered for a little while, the God of all grace, who called you to His eternal glory in Christ, will Himself perfect, confirm, strengthen and establish you. 11 To Him be dominion forever and ever. Amen.