The Imitation of Christ, by Thomas a Kempis, tr. by William Benham [1886], at sacred-texts.com
"My Son, be not curious, nor trouble thyself with vain cares. What is that to thee? Follow thou Me.(1) For what is it to thee whether a man be this or that, or say or do thus or thus? Thou hast no need to answer for others, but thou must give an answer for thyself. Why therefore dost thou entangle thyself? Behold, I know all men, and I behold all things which are done under the sun; and I know how it standeth with each one, what he thinketh, what he willeth, and to what end his thoughts reach. All things therefore are to be committed to Me; watch thou thyself in godly peace, and leave him who is unquiet to be unquiet as he will. Whatsoever he shall do or say, shall come unto him, for he cannot deceive Me.
2. "Trouble not thyself about the shadow of a great name, nor about the friendship of many, nor about the love of men towards thee. For these things beget distraction and great sorrows of heart. My word should speak freely unto thee, and I would reveal secrets, if only thou didst diligently look for My appearing, and didst open unto Me the gates of thy heart. Be sober and watch unto prayer,(2) and humble thyself in all things."
(1) John xxi. 12. (2) 1 Peter iv. 7.