The false miraculous healing will bring Seventh-day Adventists to the test of choosing between Sunday and Sabbath
“We need not be deceived. Wonderful scenes, with which Satan will be closely connected, will soon take place. God’s Word declares that Satan will work miracles. HE WILL MAKE PEOPLE SICK, and then will suddenly REMOVE from them his satanic power. They will then be regarded as healed. These works of apparent healing WILL BRING SEVENTH-DAY ADVENTISTS TO THE TEST. Many who have had great light will fail to walk in the light, because they have not become one with Christ.”—Letter 57, 1904.”
“…he [Satan] heals the diseases of the people, and then, in his assumed character of Christ, HE CLAIMS TO HAVE CHANGED THE SABBATH TO SUNDAY, and commands all to hallow the day”— GC 624.2
“The miracle-working power manifested through spiritualism will exert its influence against those who choose to obey God rather than men. Communications from the spirits will declare that God has sent them to convince the rejecters of Sunday of their error, affirming that the laws of the land should be obeyed as the law of God. They will lament the great wickedness in the world and second the testimony of religious teachers that the degraded state of morals is caused by the desecration of Sunday. Great will be the indignation excited against all who refuse to accept their testimony.” (DD 34.2)