We're discussing the salvation of Protestants, not that of Buddhists.
And again, it's a necessity of means that is normative, not absolute. A three-week old baby who dies still wet from a Catholic baptismal font has no conscious or explicit "knowledge of Christ".
You are very confused, or something worse.
Little children have infused supernatural faith given to them by the Sacrament itself. Again the Council of Trent:
whence, man, through Jesus Christ, in whom he is ingrafted, receives, in the said justification, together with the remission of sins, all these (gifts) infused at once, faith, hope, and charity. (Session 6, Chapter VII)
If they did not have faith, we could not account them as members of the faithful, nor as heirs to Christ's promise concerning those who believe in Him (St. John 3.16, etc.)
Supernatural faith is an absolute necessity of means of salvation, since without faith, no one can be justified. And without justification, no one can receive salvation.