Notice this scripture: "This is how we know who the children of God are and who the children of the devil are: Anyone who does not do what is right is not a child of God; nor is anyone who does not love his brother" (1 John 3:10, New International Version). It did not say, "This is how we save ourselves." It says, "This is how we know who the children of God are..." (1 John 3:10, emphasis mine).
Jesus said it like this, "By their fruits ye shall know them" (Matthew 7:20, emphasis mine).
In Scripture, God speaks of salvation in two ways: (1) that salvation is by grace through faith (Ephesians 2:8‑9) and (2) in terms of the good works that every saved person will perform (Ephesians 2:10). Why are we afraid to speak of the fruit of the believer? The Bible does not shy away from such a subject. Here is how we can know we are in God's kingdom and under God's rule:
1 John 2:3‑5 —  We know that we have come to know him if we obey his commands.  The man who says, "I know him," but does not do what he commands is a liar, and the truth is not in him.  But if anyone obeys his word, God's love is truly made complete in him. This is how we know we are in him.
If you know that He is righteous, you know that everyone who does what is right has been born of Him (1 John 2:29). (Doesn't this make sense? The nature of God and Christ is righteousness, and everyone who practices righteousness is giving evidence of sharing His nature or, as John says, has been born of Him).
1 John 3:5‑10 —  But you know that he appeared so that he might take away our sins. And in him is no sin.  No-one who lives in him keeps on sinning. (In Greek, this is in the present tense; this conveys continuous, or habitual, action. The Bible reader can significantly enhance their understanding of the passage by supplying the words: continuously, repeatedly, over and over again, uninterruptedly, constantly, keep on, customarily, habitually, as a lifestyle.) No-one who continues to sin (present tense) has either seen him or known him.  Dear children, do not let anyone lead you astray. He who does (present tense: repeatedly, over and over again does) what is right is righteous, just as he is righteous.  He who does what is sinful (present tense: habitual as a lifestyle because it's their nature) is of the devil, because the devil has been sinning from the beginning. The reason the Son of God appeared was to destroy the devil's work.  No-one who is born of God will continue to sin (present tense: that is, as their lifestyle, showing an unrepentant heart), because God's seed remains in him; he cannot go on sinning (present tense: uninterruptedly), because he has been born of God.  This is how we know who the children of God are and who the children of the devil are: Anyone who does (present tense) not do what is right is not a child of God; nor is anyone who does not love (present tense) his brother. (John says, "This is how we know who the children of God are and who the children of the devil are." Those who do not practice righteousness and love show that they do not have the nature of the Father. Is evidence of the new birth not important?)
1 John 3:14 — We know that we have passed from death to life, because we love our brothers. Anyone who does not love remains in death.
1 John 4:6 — We are from God, and whoever knows God listens to us (the apostles); but whoever is not from God does not listen to us (the apostles). This is how we recognize the Spirit (or spirit) of truth and the spirit of falsehood.
1 John 4:8 — He that loveth not knoweth not God; for God is love. (Love is the mark of a believer, for the nature of God is love.)
1 John 5:2 — This is how we know that we love the children of God: by loving God (present tense: and continually loving Him) and carrying out (present tense: and continuing to keep) his commands.
John 5:18‑19 — We know that anyone born of God does not continue to sin (present tense: as a lifestyle, showing an unrepentant heart); the one who was born of God keeps him safe (King James Version — keepeth himself, present tense: and continues to keep himself), and the evil one cannot harm him.  We know that we are children of God, and that the whole world is under the control of the evil one.
WHY DID THE APOSTLE JOHN SHARE ALL THESE THINGS WITH US? I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life (1 John 5:13).
Conclusion: Righteousness, holiness, love, the fruit of God's Spirit are evidences of the new birth. You yourself have no confidence that you belong to Him (God) while practicing an ungodly lifestyle. The conscience condemns, and there is no confidence toward God. The Apostle Peter admonishes you to make your calling and election sure (2 Peter 1:10); i.e., assure your heart that you really do belong to Him by a lifestyle that corresponds to the glorious Gospel. I did not say, "This is how we are saved"; I said, "This is how we know we belong to Him."
- Read Acts 8:13, 18‑22."13Then Simon himself believed also: and when he was baptized, he continued with Philip, and wondered, beholding the miracles and signs which were done. 18And when Simon saw that through laying on of the apostles' hands the Holy Ghost was given, he offered them money, 19Saying, Give me also this power, that on whomsoever I lay hands, he may receive the Holy Ghost. 20But Peter said unto him, Thy money perish with thee, because thou hast thought that the gift of God may be purchased with money. 21Thou hast neither part nor lot in this matter: for thy heart is not right in the sight of God. 22Repent therefore of this thy wickedness, and pray God, if perhaps the thought of thine heart may be forgiven thee." - Acts 8:13, 18‑22First John is speaking about the "fruit," or evidence of a true believer. These are all issues that spring from the heart. When a believer's heart is found not to be right (such as Simon's), what are they to do?Answer
- Read 2 Peter 1:5‑11."5And beside this, giving all diligence, add to your faith virtue; and to virtue knowledge; 6And to knowledge temperance; and to temperance patience; and to patience godliness; 7And to godliness brotherly kindness; and to brotherly kindness charity. 8For if these things be in you, and abound, they make you that ye shall neither be barren nor unfruitful in the knowledge of our Lord Jesus Christ. 9But he that lacketh these things is blind, and cannot see afar off, and hath forgotten that he was purged from his old sins. 10Wherefore the rather, brethren, give diligence to make your calling and election sure: for if ye do these things, ye shall never fall: 11For so an entrance shall be ministered unto you abundantly into the everlasting kingdom of our Lord and Saviour Jesus Christ." - 2 Peter 1:5‑11What is the proof, or evidence, that a person is really among those God has called and chosen?Answer
- Read Matthew 25:34‑40."34Then shall the King say unto them on his right hand, Come, ye blessed of my Father, inherit the kingdom prepared for you from the foundation of the world: 35For I was an hungered, and ye gave me meat: I was thirsty, and ye gave me drink: I was a stranger, and ye took me in: 36Naked, and ye clothed me: I was sick, and ye visited me: I was in prison, and ye came unto me. 37Then shall the righteous answer him, saying, Lord, when saw we thee an hungered, and fed thee? or thirsty, and gave thee drink? 38When saw we thee a stranger, and took thee in? or naked, and clothed thee? 39Or when saw we thee sick, or in prison, and came unto thee? 40And the King shall answer and say unto them, Verily I say unto you, Inasmuch as ye have done it unto one of the least of these my brethren, ye have done it unto me." - Matthew 25:34‑40What are the qualities demonstrated by the believer in these verses?Answer
- Read John 13:35."By this shall all men know that ye are my disciples, if ye have love one to another." - John 13:35Jesus' disciples are known by what?Answer
- Read Matthew 7:21‑23."21Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven. 22Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works? 23And then will I profess unto them, I never knew you: depart from me, ye that work iniquity." - Matthew 7:21‑23Why were these individuals turned away from God's kingdom?Answer
- Read John 14:23."Jesus answered and said unto him, If a man love me, he will keep my words: and my Father will love him, and we will come unto him, and make our abode with him." - John 14:23If a person loves Jesus, what will they do?Answer
- Read Acts 26:20."But showed first unto them of Damascus, and at Jerusalem, and throughout all the coasts of Judaea, and then to the Gentiles, that they should repent and turn to God, and do works meet for repentance." - Acts 26:20What is this verse saying?Answer
- Read James 2:14, 17."14What doth it profit, my brethren, though a man say he hath faith, and have not works? can faith save him? 17Even so faith, if it hath not works, is dead, being alone." - James 2:14, 17If your faith is not followed by good works, or actions, then what kind of faith is it?Answer