“If we walk in the light as He Himself is in the light, we have fellowship with one another, and the blood of Jesus His Son cleanses us from all sin” (1 John 1:7 ).
God is light, and His children share His nature.
First John 1:5 aptly describes God’s nature as “light” (truth and holiness). Because they partake of His nature (2 Peter 1:4), His children also walk in the light. It must be understood that we don’t become God’s children by walking in the light, but rather we walk in the light because we are His children. The Greek verb describes continuous action and could be translated, “If we habitually or continuously walk in the light. . . .” It’s an indicator of character; a definition of a true Christian, just as walking in the darkness characterizes unbelievers.
Two significant benefits come to believers because they walk in the light. These are privileges granted only to Christians; unbelievers who think they possess them deceive themselves.
First, believers experience fellowship with God. “One another” in 1 John 1:7 does not refer to other Christians. Although it is certainly true that believers enjoy fellowship with each other, that is not what this verse is teaching. The use of the pronoun “his” later in the verse makes it clear that the fellowship in view here is with God. That fellowship is mutual, “with one another.” Believers share a common life with God, experience His presence through the indwelling Holy Spirit, and commune with Him through prayer and the reading of His Word.
Second, believers experience cleansing from sin. “The blood of Jesus His Son” is the agency of that cleansing. Christ’s blood is symbolic of His sacrificial death on the cross, where full payment was made for believers’ sins. Once again it must be noted that walking in the light does not earn forgiveness; rather, forgiveness is freely granted to those who walk in the light (who are Christians).
In view of those glorious truths, I would leave you today with the challenge of the apostle Paul: “Now you are light in the Lord; walk as children of light” (Eph. 5:8 ).
https://www.gty.org/library/devotionals/strength-for-today