"When we are completely converted, when we cease our idolatry, when we choose to love God with all our hearts, minds, and strength, (instead of our institutions and entertainments) then, suddenly, all these great blessings become a reality. The gospel of Jesus Christ really does work. God really does reveal Himself to man."
I now add: not only does the gospel of Jesus Christ work, and not only does God reveal Himself to man, but the gifts and fruits of the Spirit ARE still vibrant and present in the lives of the followers of Christ . . . people are healed miraculously, visions are seen, prophecies spoken, lives change in a moment, people receive the second baptism and become completely new creatures in Christ. It happens all the time . . . outside of the Church of Jesus Christ of Latter-day Saints. Mormons, we don't have a monopoly on salvation. We never have.
"I was answered that I must join none of them, for they were all wrong; and the Personage who addressed me said that all their creeds were an abomination in his sight; that those professors were all corrupt; that: “they draw near to me with their lips, but their hearts are far from me, they teach for doctrines the commandments of men, having a form of godliness, but they deny the power thereof.” (Joseph Smith History 1:19)
Despite those words, God has never withheld the manifestation of His Spirit from those who are worthy. Not everyone in "those other churches" clings to the creeds thereof. Those who do, miss out. Just as idolatrous members of the LDS church who speak and praise men to the nearly complete exclusion of Christ utterly miss the point of everything they're doing. Their belief in the Book of Mormon won't save them if they spend their time in worship focused on the wrong target.
Those signs and wonders are in the Book of Mormon because they're supposed to be happening wherever there are followers of Christ. And yet it's totally absent in our discourse today. We sometimes mention, in language deeply shrouded with mystery, and reverence thick & heavy, one of the rare and precious times that we really, truly, personally felt God's love. Jesus said He would be as a fountain of Living Water, springing up continually in us unto everlasting life! Where's the rationing and restraint in that? To a desert-dwelling people, a fountain is a gaudy and murderous profligacy. That parable was to them. To show them the very beginning of Jesus' generosity and eagerness to pour His love into us. To continually baptize us into new life as His mercy is renewed every morning.