John 14:10

οὐ πιστεύεις … ἐστι; This unbelief was involved in Philip's question, but when the question of the mutual indwelling of the Father and Jesus was thus directly put to him, he would have no doubt as to the answer. Cf. John 10:38. The fact of the union is indisputable; the mode is inexplicable; some of the results are indicated in the words: τὰ ῥήματα … τὰ ἔργα. See John 7:16-18 and John 5:19. The mutual indwelling is such that everything Jesus says or does is the Father's saying or doing. This was so obvious that Jesus could appeal to the works He did in case His assertion was disbelieved.