You have an anointing from the Holy One, and you know the truth.
In the Old Testament, kings and priests were anointed with oil when they were installed into their offices. The anointing with oil was used for medicinal purposes in healing (Luke 10:34; James 5:16). Jesus anointed a blind man’s eyes with spital when he healed him (John 9:6). Jesus was "anointed" with the Holy Spirit (Acts 10:38). Christians are "anointed" by God (2 Corinthians 1:21-22). Some suggest that the "anointing" mentioned by John has to be the anointing of the Holy Spirit because of the association of the Holy Spirit in anointing. Some say that it refers to the miraculous gifts of the Holy Spirit given to Christians during the first century. This position is untenable because John says that this anointing makes it possible for these Christians to "know all things," and only "some" of the early Christians received the spiritual gifts that had to do with knowledge (1 Corinthians 12:4-10; 1 Corinthians 12:28). Others say that the anointing indicates those who received the "gift of the Holy Spirit," which is common to all Christians. Again, this anointing would give every Christian a hotline to revelation. To refer the anointing to the reception of the Holy Spirit, either miraculously or otherwise, seems contrary to the teaching of God’s word.