“Enter ye in at the strait gate: for wide is the gate, and broad is the way, that leadeth to destruction, and many there be which go in thereat: Because strait is the gate, and narrow is the way, which leadeth unto life, and few there be that find it.” Matthew 7:13-14
When Jesus talked about just a few people entering ‘the narrow gate’, this would have been understood as referring to a ‘remnant’ of Israel escaping the imminent judgment on their nation. The concept of a faithful remnant in Israel had always been a part of prophetic thinking (e.g. Isaiah 10.20; Jeremiah 6.9; Ezekiel 9.8). Jesus was predicting that only a few Israelites would make it through the ‘narrow gate’ and avoid ‘the coming wrath’.
From “Jesus and the End of Death” by Mark Edward. http://amzn.to/2zeva0A