Attending Catholic Mass, one will hear from time to time a prayer (below) that I think beautifully expresses what is called soteriological inclusivism, a view that I identify broadly within. Inclusivism lies between exclusivism (which holds that being saved requires (except perhaps in infants or intellectually challenged persons) ‘conscious knowledge’ of Christ as Lord and Saviour) and universalism (which holds that God’s grace is so overwhelmingly powerful that it will win over against the wills and decisions of all people eventually, whether before death, or in some kind of post-mortem scenario). Inclusivism expresses a hope, or perhaps a conviction, that whilst God will not ‘force’ his grace universally onto all people, it is nonetheless possible for some to, as C.S. Lewis put it somewhere, belong to Christ without themselves knowing it.
God alone may know the faith of some who don’t let others know it, or perhaps cannot even let themselves admit it. A friend of mine once called this being “a believer who couldn’t believe”. Here’s how it is expressed in the Catholic liturgy (as found in my copy of the 1982 version of The Sunday Missal; Eucharistic Prayer IV), when the priest offers prayers for the dead:
Remember those who have died in the peace of Christ
and all the dead whose faith is known to you alone.