The invitation in v. 5 displays the purpose of this section: “come, let us walk in the light of the Lord.”  That is addressed to God’s people.  This invitation follows the description of what will happen as “all the nations flow to” the mountain of the house of the Lord (v. 2).  It’s interesting that the reaction of the nations becomes a model for all God’s people.  Again, the assumption of this section is that there are many among God’s people that are not currently walking in the light of the Lord.  In light of what the nations will do in the future, it’s time for God’s true Believers to be sure their lifestyle matches their profession.  One way to move to the Gospel is through the imagery of v. 2 and the Son of Man being “lifted up” to draw all men to Him (cf. John 3:14; 12:32).