Audio commentary on this verse

Note 33 at Rom. 8:16: First John 5:10 says, "He that believeth on the Son of God hath the witness in himself." John goes on to say in verse 13, "These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life." So, the Spirit bearing witness with our spirit is to assure us that we are the children of God (1 Jn. 3:19).