Romans 8:16

The Spirit of adoption doth not only excite us to call upon God as our Father, but it doth ascertain and assure us (as before) that we are his children. And this it doth not by an outward voice, as God the Father to Jesus Christ; nor by an angel, as to Daniel, and the virgin Mary; but by an inward and secret suggestion, whereby he raiseth our hearts to this persuasion, that God is our Father, and we are his children. This is not the testimony of the graces and operations of the Spirit, but of the Spirit itself. Conceive it thus; A man's own spirit doth witness to him his adoption, he finds in himself, upon diligent search and examination, the manifest signs and tokens thereof. But this testimony of itself is weak, and Satan hath many ways and wiles to invalidate it; therefore, for more assurance, it is confirmed by another and greater testimony, and that is of the Spirit himself; he witnesses with our spirits, and seals it up unto us; he first works grace in our hearts, and then witnesseth to it. This testimony is not alike in all believers, nor in any one of them at all times; it is better felt than expressed. He witnesseth to our spirit (so some read) by a distinct and immediate testimony, and witnesses with our spirit (so the word properly signifies) by a conjunctive and concurrent testimony.