Fire is a purifier. 1 Cor 3:11-15, For other foundation can no man lay than that is laid, which is Jesus Christ. Now if any man build upon this foundation gold, silver, precious stones, wood, hay, stubble; (another gospel) Every man's work shall be made manifest; for the day shall declare it, because it shall be revealed by fire, and the fire shall try every man's work of what sort it is. If any man's work abide which he hath built thereupon, he shall receive reward. If any man's work shall be burned, he shall suffer loss (non fellowship with God) but he himself shall be saved; yet so as by fire.
Matt 7:13-14, fits in with this same teaching; All of those that go into both gates are born again children of God. Those that go in the wide gate are those that are teaching and preaching the false doctrine of eternal salvation by the good works of man, and those that go in the straight gate are those that have been revealed, and understand, the true doctrine of Christ, which leads them to an abundant and peaceful life as they sojourn here on earth. Both gates have inherited eternal life, but those in the broad way are not fellowshipping with their God.