Titus 2:11

For the grace of God hath appeared, bringing salvation to all men,

This is a reference to the Incarnation, the First Advent of the Son of God, whose visitation upon our planet came directly and solely from the grace of God. With his birth at Bethlehem, it was appropriate to say that salvation had indeed been brought to all men. As Simeon said:

Now lettest thou thy servant depart, Lord, According to thy word, in peace; For mine eyes have seen thy salvation, Which thou hast prepared before the face of all peoples (Luke 2:29,30).

When Simeon said this, all men had not been saved; and at the time of Paul's writing here, nor at any time ever, was it ever true that all men are saved. Yet God has established the charter of human redemption in dimensions large enough to accomplish the salvation of every man ever born on earth. The mystery of why so many are still unsaved is not ours to unravel.

Bringing salvation to all men... As Spence commented:

This is another of those hard sayings which have been pressed into the service of that kindly but erring school of expositors which shuts its eyes to the contemplation of the many unmistakable sayings which warn the impenitent and hardened sinner of the sad doom of eternal death.[30]