“Not everyone who says to Me, ‘Lord, Lord,’ shall enter the kingdom of heaven, but he who does the will of My Father who is in heaven. Many will say to Me in that day, ‘Lord, Lord, have we not prophesied in Your name, cast out demons in Your name, and done many wonders in Your name?’ And then I will declare to them, ‘I never knew you; depart from Me, you who practice lawlessness!"
Can more fearful words be imagined? “Many” will call Jesus Lord, and yet go to hell forever!
Such a passage begs every professing Christian to ask this very sobering question: how do you know that you are not deceived? If a deceived person by definition does not know that he is deceived, then how can you know that you are not one of them?
In Luke 13:24-30, Jesus again says that on the Day of Judgment “many...shall seek to enter” the kingdom of heaven “and shall not be able”. They will cry out to Him, “Lord, open up to us...we have eaten in Your presence and Thou hast taught in our streets” and again Christ will respond to them, “depart from Me, all ye workers of iniquity.”
What a horrible delusion! These people apparently thought that they were Christians for they called Jesus “Lord”, and they apparently thought that they were Christians for some time for they did “many” works in His name. These professing Christians spent some amount of time convinced that they were on their way to heaven, when all the while they were on their way to hell. So how can we know that we are not in the same situation?
The Bible commands us to test ourselves to see if we are truly in the faith (2 Corinthians 13:5; 2 Peter 1:10), but how can we do this? Can we know for sure that we have been born again or should we just trust our subjective feelings and hope that we are right in the end, or is there something more concrete we can rest our minds upon? While there is certainly a subjective aspect to true salvation, wouldn’t it be foolish to conduct our “test” solely on the basis of such evidence? Doesn’t Proverbs 28:26 tell us that "He that trusteth in his own heart is a fool..."?
One answer to this puzzling question is found in Matthew 7:16-20, and is repeated in Matthew 12:33-35 where it said that “a tree is known by its fruit.”
Consider this for a moment; a tree brings forth fruit according to its nature. An orange tree will grow oranges. Why? Because it is an orange tree by nature. An apple tree will grow apples. Why? Because it is an apple tree by nature. If you put fruit salad and raw meat in front of a lion, it will always eat the raw meat. Why? Because that is its nature. The nature of a thing determines what it does.
Likewise, when a person truly becomes a Christian they become “partakers of the divine nature” (2 Peter 1:4). In other words, by an act of God, they come to share in God’s moral nature and thus begin to resemble Him morally; they begin to like what He likes, love what He loves, hate what He hates, etc.
This is why they are called “children of God” (1 John 3:10). Just as the children of men resemble their natural parents, the children of God resemble their supernatural Parent. They will begin to hate sin just as their Father hates sin. They will begin to love holiness just as their Father loves holiness. They will begin to love God’s other children just as their Father loves His other children. Do you see the relationship to trees and fruit? Do you wish to see if a tree has the nature of an orange tree? Then look at its fruit. Do you wish to know if you partake of the divine nature? Then look at the fruit of your life.