Walking in light is not a sinless pipedream. It is not theological clarity on every question. It is the stumble-free offer that accompanies salvation. The person who is able to keep us from stumbling would not be one of the stumblers, would he?
Can anyone see who gets ongoing cleansing?

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 CSB

The righteous expect to be kept. David put it in a michtam (there are only 6 michtamim). Unlike many of our comrades in arms we have to make our way in concert with Fact. Forecast, and Faith.

For [[Fact] thou hast delivered my soul from death: [[Forecast] wilt not thou deliver my feet from falling, [[Faith] that I may walk before God in the light of the living?

Psalms 56:13

Since David knew something about salvation- the man even secures his mortal enemy and his mortal enemy’s progeny- he deposits a query in the negative: “will you not keep my feet from falling?” The eternal salvation has the answer: our Keeper does not nod off or sleep.

I cannot believe that my falling has more power than God’s keeping. God is author and finisher. The Help we have to stsy on our feet is perfect: the Holy Spirit. Let’s twist and shout; let us dance to display the majesty of our new gospel-clad feet. This is comely wordless praise!