Enter through the narrow gate. For wide is the gate and broad is the road that leads to destruction, and many enter through it. But small is the gate and narrow the road that leads to life, and only a few find it.
The small gate and narrow road which only a few find is simply about being true followers of Christ. And with an ear to his teaching, in context: the Sermon on the Mount.
Many might have faith enough to be included in God’s salvation and kingdom in Christ. Just to have faith is no shoe in, though. Many believed in Jesus at one point, but turned against him. We should never be satisfied with simply just believing so that our after life is supposedly taken care of. That is not the faith required. Our faith might start small, and often does. We are all on a spiritual journey, for sure. But the faith Jesus desires is a faith of following him. The way of the cross; the Jesus way. In and through Jesus.