Just read the book of 1 John honestly (and do some research on 1:8).
1:6 If we say that we have fellowship with Him, and walk in darkness, we lie and do not practice the truth.
2:1 My little children, these things I write to you, so that you may not sin.
2:4 He who says, “I know Him,” and does not keep His commandments, is a liar, and the truth is not in him. [Commandments such as Matthew 5:48, "Therefore be perfect as your Father in heaven in perfect."]
[b]2:6 He who says he abides in Him ought himself also to walk just as He walked.[/b]
2:15 Do not love the world or the things in the world. If anyone loves the world, the love of the Father is not in him.
[b]2:29 If you know that He is righteous, you know that everyone who practices righteousness is born of Him.[/b]
3:4-9 Whoever commits sin also commits lawlessness, and sin is lawlessness. And you know that He was manifested to take away our sins, and in Him there is no sin. Whoever abides in Him does not sin. Whoever sins has neither seen Him nor known Him.
Little children, let no one deceive you. He who practices righteousness is righteous, just as He is righteous. He who sins is of the devil, for the devil has sinned from the beginning. For this purpose the Son of God was manifested, that He might destroy the works of the devil. Whoever has been born of God does not sin, for His seed remains in him; and he cannot sin, because he has been born of God.
3:21 Beloved, if our heart does not condemn us, we have confidence toward God.
3:24 Now he who keeps His commandments abides in Him, and He in him. And by this we know that He abides in us, by the Spirit whom He has given us.
4:8 He who does not love does not know God, for God is love.
[b]4:17 Love has been perfected among us in this: that we may have boldness in the day of judgment; because as He is, so are we in this world.[/b]
4:21 And this commandment we have from Him: that he who loves God must love his brother also.
5:2-3 By this we know that we love the children of God, when we love God and keep His commandments. For this is the love of God, that we keep His commandments. And His commandments are not burdensome.
[b]5:18 We know that whoever is born of God does not sin; but he who has been born of God keeps himself, and the wicked one does not touch him.[/b]
ect, ect.