The assumption is that there are two gates that lead to heaven. The wide gate is all religions of works and self righteousness that lead to destruction. Jesus said that the narrow gate is to follow him by faith, which is the only way to salvation. This is the narrow gate. It is by Grace alone, but it is not an easy path. It takes knowledge of God’s truth, repentance, and submission to Jesus’s path, and not our own. Thank you Jesus, for you Holy Spirit, that helps us on that narrow path, to all who choose to follow it.

“Enter through the narrow gate; for the gate is wide and the way is broad that leads to destruction, and there are many who enter through it. For the gate is small and the way is narrow that leads to life, and there are few who find it.
Matthew 7:13‭-‬14 NASB
https://bible.com/verse-of-the-day/mat.7.13-14/39671