The Apostle John loved Jesus’ description of Himself as the ‘Light of the World’ (in 16 verses in John’s Gospel and 5 verses in 1 John).  In a spiritually dark world, even though it was very religious, Jesus had stood out as being pure in every way, truthful, visionary, guiding, clear and revealing.  As John says in 1 John 1:5, “This is the message we have heard from him and declare to you: God is light; in him there is no darkness at all.”  Having lived with Jesus for almost three years, John knew that there was no corner of his Master’s life which was dark or even slightly shady.
 
Although the crowds did not realise it, they had the privilege of being with the Light of the World.  But He would soon be gone.  His crucifixion would be a dark day (Luke 23:44-46).  So He urged them to trust in Him while He was still with them: knowing that all who do so will be born again (John 3:4-6) and become children of God for ever (John 1:12 ).  His words were made all the more profound because, having spoken, He went away and nobody could find Him.  John knew that to walk without Christ was hopeless and futile, but to walk with Him is purposeful and joyful.  So John quotes Jesus speaking out of the words of his gospel, ‘Put your trust in the light while you have it’.
 
Many people today, like the crowds around Jesus, present all kinds of reasons for doubting Jesus.  But their real problem is not intellectual but moral.  Will they submit to Jesus or not?  Those who do are born again as children of God and enjoy His company until they enter His presence.  Therefore, Jesus urged them to put their trust in Him while they had the opportunity (John 14:1). It was a matter of urgency not just a consumer preference (Jonah 3:8).

Alas, Christians sometimes forget that unless their friends trust in Jesus they will be overtaken by the darkness for ever.  Although it is right to respect people’s opinions, it is also eternally important to urge them to put their trust in Jesus.  So pray for your friends who do not yet know Jesus; be ready to explain to them that Jesus is the Light of the World, and that they need to put their trust in Him while there is still opportunity (perhaps you could start by inviting them to watch www.crosscheck.org.uk).