Commentaries:
The first-mentioned source of curses is not public or institutionalized idolatry, as practiced by the world's religions, but hidden idolatry, that clandestine—maybe subliminal—elevation of anything before the true God. The reference is to the breaking of the first and second commandments (Exodus 20:2-6). In a modern context, such covert idolatry would include placing career, family, pleasure, or even, more subtly, social status in the church, above the worship of the true God.
Charles Whitaker
Unity and Division: The Blessing and the Curse (Part Four)
God does care how we worship Him; He gives specific commands about how He wants to be glorified according to His standards and not our own. It does matter whether or not we share in the celebration of this world's pagan religious holidays. Though the Bible—the Word of God—makes no direct references to New Year's Eve, Lent, Easter, Halloween, or Christmas, the origins of these pagan holidays are mentioned as being abominations to God.
Martin G. Collins
Pagan Holidays
Looking at the underlying commonality of the Ebal-curses—that they focus on secret sin—we may conclude that the six tribes on Ebal represent those church members whom we could call “wolves in sheep's clothing,” in whom God finds unrepented sin, individuals living a secret life, closeted in some way, hypocrites.
Conversely, we may conclude that the six tribes atop Mount Gerizim symbolize those people in God's church who exhibit sincerity and wholeness of heart, unwavering commitment to keeping the principle inherent to the Feast of Unleavened Bread—and, by extension, living their entire lives—“not with the old leaven, the leaven of malice and evil, but with the unleavened bread of sincerity and truth” (I Corinthians 5:8).
Those on Gerizim, unlike their fellows on the Mount of Cursing, represent individuals who break their bread with “singleness of heart” (Acts 2:46), fully committed to abandoning all sin, no matter how stubbornly closeted it may have been at one point in their lives, no matter how tenacious its addiction, no matter how much carnal pleasure it might bring. On Gerizim stand, symbolically, those of God's people who, recognizing the damnation of the charade, have firmly rejected living a double-life. Those who so shun sham and find no pleasure in the mask really do stand on the Mountain of Blessing!
Charles Whitaker
Unity and Division: The Blessing and the Curse (Part Five)
