Clement of Alexandria (150-215 AD) states that by the Apostle John saying here that “God is light,” He does not express God’s divine essence but declares God’s majesty. It is because he has implied Holiness, which is the most excellent attribute in the view of mankind. It’s the same when the Apostle Paul speaks of “light inaccessible.” But John also in this same Epistle says, “God is love:” pointing out the excellencies of God, that He is kind and merciful; and because He is light, makes people righteous, according to the advancement of the soul, through charity. God, then, who is overwhelming respecting His substance, which is Light.
And that is because, says Clement, “in Him is no darkness at all,” — that is, no immoral passions, no thoughts of evil against anyone. On the contrary, He destroys no one but gives salvation to all. Moreover, Light signifies either the principles of the Law, faith, or doctrine. Darkness is the opposite of these things. Not as if there were another way, since there is only one way according to God’s Word. For the work of God is unity. Double-mindedness and all else that exists, except unity, arises from stubbornness on its own.
In his message on salvation by faith, John Wesley (1703-1791) made it clear that all of God’s grace, bounty, and favor are altogether underserved. That’s because no person has the means to atone for their sins, not even through works. Becoming right before God is the only way for any person to secure justification and redemption. But it only comes through God’s grace and mercy. And that becomes a reality once a person puts their faith in Jesus the Anointed One and His work on Calvary.
Again, says Wesley, they are saved from the power and guilt of sin through this faith. So, the Apostle John declares, “You know that the Anointed One appeared in order to take away sins, and that sin does not exist in Him. So, everyone who lives in union with the Anointed One does not go on sinning. But if they do, it means they never met Him and know nothing about Him. Don’t let anyone betray you, my children! In God’s eyes, every person who lives upright is right, just as the Anointed One is righteous. Those who continue to sin belong to the Devil because the Devil sinned from the beginning. The Son of God appeared for this very reason, to destroy what the Devil had done. Those who are God’s children do not continue to sin, for God’s very nature is in them, and because God is their Father, they cannot continue to sin. Let me say that again, none of God’s loyal children keeps on sinning, for the Son of God keeps them safe, and the Evil One cannot harm them. 
James Macknight (1721-1800) points out that the term “take away sins” signifies to procure the pardon of sin under the First Covenant. But here, in this fifth verse, the Apostle John seems to attach a broader meaning to the phrase, “take away our sins.” It certainly applies to the substance that our sins, like a heavy load, are lifted off the one crushed beneath it. By the manner in which John introduces it here, it seems apparent that it implies that the Anointed One was purposely manifested in the flesh and died in the flesh to take away the power and the punishment of sin. Therefore, says Macknight, assured hope of a pardon made possible by the atonement made for sin by the death of the Anointed One should be a strong encouragement for sinners to repent in order to escape everlasting punishment and receive eternal life.
William E. Jelf (1811-1875) has quite a bit to say about verse five. For him, this does not mean that it is impossible for one who is in union with the Anointed One to sin. We cannot limit the Greek word hamartia to willful sin. Such random limitations lead us from the real sense of the passage and are founded on a principle of interpretation that destroys Revelation. We find the key to the whole narrative in the Greek verb ménein, which means “to stay or abide.” The solution, says Jelf, is provided by Augustine, “in quantum in Christo manet, in tantum non peccat” (“in so far as he remains in Christ, in that proportion does not sin”). In this way, the Greek noun hamartia (“errors, mistakes, missing the mark”) has a natural sense of continuous sinning.
It means that even after a person has become a Christian by being made a new creature by the indwelling of the Anointed One and the presence of His Spirit, they can allow an inward desire to develop itself into actual sin. It results from encouraging instead of resisting the urge or being comfortable while tolerating the passion. Secretly, they may be wishing that they might sin without offending God, or in some such way let go their fellowship with the Anointed One, despite the Spirit of Grace. They might have resisted and stifled the desire through such grace before it developed into an act. And in proportion to the seriousness of the sin, they must have departed, severed their union with the Anointed One, ceasing to be a spiritually motivated Christian.
It is in perfect harmony with the rest of the Gospel scheme. Self-experience establishes what the Apostle John says: that the Christians’ external behavior is a sure and accurate index of their internal state, expressed in verse seven. In the past, some people taught that outward conduct is no evidence of the inward conditions; God’s chosen may break the law without any fear for decreased assurance of their state of grace. Some conclude that a loyal Christian does not sin on purpose, but instead makes mistakes because they misinterpret the same teaching. It is true that the Christian’s will is against sin and still does wrong despite their Christian nature. But still, it is the person who sins. God will judge each individual for breaking His Law. The question is whether the Christian element of faith, the Christian principle of remaining in union with the Anointed One, is the strongest and most natural in them, and their practical acts decide this.
Richard Tuck (1817-1868) mentions that in the Apostle John’s day, there were so-called disciples of the Anointed One who so emphasized personal refinement and meticulousness that they thought it was impossible for anything of a spiritual nature to inhabit a human. They could not believe that anything divine could be housed in sinful human flesh. What makes this so ironic is that these very same individuals who claimed to be so highly spiritual were, in fact, living the most immoral and depraved lives. That’s why they refused to accept that the Son of God became a son of man. However, here is John, the most spiritual of all the original Apostles, insisting on the human nature of our Lord. However, His incarnation was nothing to be ashamed of because there is very little for a person to be ashamed of except sin. But, on the other hand, there is nothing nobler than a sanctified human nature.
John Stock (1817-1884) shares his view that the holiness of our Lord proves His deity, more so than do His miracles. Humanity since the fall was never holy. Only Jesus rightly claimed equality with God. No one could convince Him of sin, in so doing, though for such a clean life, dirty hands crucified Him. Our Lord indeed had the “semblance of a sinner; was made in the likeness of sinful flesh; and for sin, God condemned sin in His flesh:” “He did not take on Him the nature of angels, but He took on Him the seed of Abraham,” “and made like us, His brothers and sisters, in every way.” He had all our sinful infirmities, knew our human necessities, and was capable of death, but yet, He was in His birth a holy thing, and sin was ever at an immeasurable distance from Him. Satan had no power over Him, and though a friend of publicans and sinners, He was no patron of their acts; but came to save His people from their sins, saying, “I desire mercy, not sacrifice.” Oh! How pure is the Anointed One! How great is His glory in this, as in all things! So great is the honor is to be His follower and, in any way, be conformed to the image of God’s only Son. He is the firstborn among many brethren; and who gave Himself for us, to rescue us from constant falling into sin and make us His very own people, with cleansed hearts and genuine enthusiasm for doing kind things for others. 
 2 Corinthians 4:4
 1 John 1:5
 Fragments of Clemens Alexandrinus, Comments on the First Epistle of John, p. 1160
 1 John 3:5-9
 1 John 5:18
 Works of John Wesley: Vol. 5, Sermon 1, p. 69
 See John 1:29; 1 Peter 2:24
 See Titus 2:14
 James Macknight: First Epistle of John, op. cit., p. 68
 Jelf, W. E., Commentary on the First Epistle of St. John, op. cit., pp. 42-43
 Tuck, Richard: A Preacher’s Complete Homiletical Commentary, op. cit., p. 295
 Acts of the Apostles 2:23
 Romans 8:3
 Hebrews 2:16
 Ibid. 2:17
 John 14:30
 Matthew 1:21; 9:13
 Romans 8:29
 Titus 2:14
 Stock, John: An Exposition of the First Epistle General of St. John, op. cit., pp. 252-253