“The time of the Holy Spirit, or the time in which communication was needed between the illusion and the truth, must end in order for the truth to become the one reality.” (ACOL, Treatise on the Personal Self, 17.8)
Truth is the one reality. And it comes, for many of us, now, after the time of the Holy Spirit and in the time of Christ. We thought that we needed an intermediary, and indeed we did. We would have been too terrified by a direct approach to God, a course that Jesus says would have been more traumatic than beatific. So, at the point of the illusion of separation, God created the Holy Spirit, an intermediary between Him and us. We are not afraid of the Holy Spirit. We do not feel uneasy in this manner of communication.
But now we are moving beyond, into true reality. We are in the time of Christ, and we listen to the indwelling spirit, the inner Christ Self. This form of guidance can less be seen as exterior to ourselves (though in truth the Holy Spirit also is not separate from us).
In the time of the Holy Spirit, He mediated between illusion and truth. But we are heading into truth without mediation now. We are strong enough to do so. God knows His children. We will head into our true reality with the strength that only God can imbue in us. And when we are strong on the inside, invulnerable, we will know the Christ Self for the first time.