Another source of danger against which we should be constantly on guard is the reading of infidel authors. Such works are inspired by the enemy of truth, and no one can read them without imperiling the soul. It is true that some who are affected by them may finally recover; but all who tamper with their evil influence place themselves on Satan's ground, and he makes the most of his advantage. As they invite his temptations they have not wisdom to discern or strength to resist them. With a fascinating, bewitching power, unbelief and infidelity fasten themselves upon the mind.  {CT 135.3}  

     We are constantly surrounded by unbelief. The very atmosphere seems charged with it. Only by constant effort can we resist its power. Those who value their salvation should shun infidel writings as they would shun the leprosy.  {CT 136.1}

Suffer not yourselves to open the lids of a book that is questionable. There is a hellish fascination in the literature of Satan. It is the powerful battery by which he tears down a simple religious faith. Never feel that you are strong enough to read infidel books; for they contain a poison like that of asps … In reading them, you are inhaling the miasmas of hell. (Ellen White, Fundamentals of Christian Education, 93).

     Some of our teachers have been charmed with the sentiments of infidel authors. In a representation given me, I saw one holding in his hand one of these books and recommending it to our teachers as a book from which real help could be obtained along educational lines. Another was holding in His hand books of an altogether different character. He placed His hand upon the one who had recommended the infidel author, and said, "Advice of the kind you have given is opening the door for Satan with his sophistries to find easy entrance to your school. These books contain sentiments that your students should be instructed to avoid. Human minds are easily charmed with studies that lead to infidelity. These books produce in the minds of the students a distaste for the study of the word of God, which is eternal life to all who follow its instruction. Such books should not find entrance into any school where the youth are being taught to be learners of the greatest of teachers.” {CT 401.2}  

Whenever books by these infidel authors are given the precedence, and the word of God is made secondary, there will be sent out of the schools a class of students no better fitted for the service of God than they were before they received their education.  {CT 424.2}

Human minds are easily charmed by Satan's lies; and these works produce a distaste for the contemplation of the Word of God, which if received and appreciated, will ensure eternal life to the receiver. You are creatures of habit and should remember that right habits are blessings both in their effect on your own character and in their influence for good over others; but wrong habits, when once established, exercise a despotic power and bring minds into bondage. If you had never read one word in these books [by infidel authors] you would today be far better able to comprehend that Book which, above all other books, is worthy to be studied and which gives the only correct ideas regarding higher education.--6T 162 (1900).