Q. 1 John 1:5-10 seems to contradict itself. At one point it talks about walking in the light and if we say we have fellowship with Him but walk in the darkness we are liars then it says if we have no sin we are deceiving ourselves, what do these verses mean?
A. When John spoke of walking in the light he meant being born again. Jesus is the light of the world and when we’re walking with Him we’re walking in the light (1 John 1:5-7).
If we say we’re walking with Him but aren’t born again the truth is not in us (1 John 1:8).
Even if we’re walking with Him we still sin. Therefore if we confess our sins He is faithful and just and will forgive us our sins and will purify us from all unrighteousness (1 John 1:9).
If we try to say we haven’t sinned we make Him out to be a liar (1 John 1:10) because in effect we’re saying He claimed to have died for sins we didn’t commit.
By the way, this is not a confession to renew our salvation. It was guaranteed to us the moment we first believed (Ephes. 1:13-14). This confession purifies us again from the unrighteousness caused by our sin and puts us back into a state of fellowship with God.