Songfacts®:

• This song evokes images of enduring romance as Marcus Mumford sings of a relationship where the couple are united together in love.
  
  Well I know I had it all on the line
  But don't just sit with folded hands and become blind
  Cos even when there is no star in sight
  You'll always be my only guiding light
  
  An alternative interpretation is that Marcus Mumford is referring to God as his guiding light. The singer was bought up in an evangelical Christian household and he and banjo player Winston Marshall started off playing in a church worship band. Light is used to symbolize God, faith or holiness throughout the Bible and Scripture itself is referred to by the Psalmist as "a light for my path."
• "Guiding Light" was released as the lead single from Mumford & Sons' fourth studio album Delta. The track combines the folk rock sounds and acoustic instrumentation of the band's first two albums, with the more electric-based vibes of their third album 2015's Wilder Mind.
  
  Mumford & Sons explained in a track by track video interview that they "felt like there was a nugget of an idea" quite early on but struggled for months to wrestle the song into shape. The quartet tried it in lots of different ways, but "it took a good year for that idea to work sonically in the studio." The quartet "kept banging our heads against the wall" with the producer Paul Epworth and "finally felt like we got there one night when the banjo and the drums fit together for the first time and that was a cool moment in the record-making process."
• The song's repeated imagery of a transition from darkness into light was inspired by some of the difficult issues the band faced, including death, depression and divorce. It's likely the lyrics were in part inspired by the Grenfell Tower fire in London, which claimed 72 lives in June 2017. Marcus Mumford personally witnessed the tower block being consumed by flames from the window of his London apartment and immediately committed himself to the relief effort.