Simeon was practically calling Him the "Divine Disturber," Who would provoke human hearts either to be good or evil. Once confronted with Him, they must subscribe to light or darkness. Before everyone else they can be "broadminded"; but His Presence reveals their hearts to be either fertile ground or hard rock. He cannot come to hearts without clarifying them and dividing them; once in His Presence, a heart discovers both its own thoughts about goodness and its own thoughts about God.
This could never be so if He were just a humanitarian teacher. Simeon knew this well, and He told Our Lord's mother that Her Son must suffer because his life would be so much opposed to the complacent maxims by which most men govern their lives. He would act on one soul in one way, and on another in another way, as the sun shines on wax and softens it, and shines on mud and hardens it. There is no difference in the sun, only in the objects on which it shines. As the Light of the World, He would be a joy to the good and the lovers of light; but He would be like a probing searchlight to those who were evil and preferred to live in darkness. The seed is the same, but the soil is different, and each soil will be judged by the way it reacts to the seed. The will of Christ to save is limited by the free reaction of each soul either to accept or reject. That was what Simeon meant by saying:The secret thoughts of many will be laid bare. Luke 2:35
... Simeon also said that the Babe would disclose the true inner dispositions of men. He would test the thoughts of all who were to encounter Him. Pilate would temporize and then weaken; Herod would mock; Judas would lean to a kind of greedy social security; Nicodemus would sneak in darkness to find the Light; tax collectors would become honest; prostitutes, pure; rich young men would reject His poverty; prodigals would return home; Peter would repent; an Apostle would hang himself. From that day to this, He continues to be a sign to be contradicted. It was fitting, therefore, that He should die on a piece of wood in which one bar contradicted the other. The vertical bar of God's will is negated by the horizontal bar of the contradicting human will. As the Circumcision pointed to the shedding of blood, so the Purification foretold His Crucifixion.
Life of Christ by Fulton Sheen