“However, when He, the Spirit of truth, has come, He will guide you…” (John 16:13 NKJV)
“But the Helper, the Holy Spirit, whom the Father will send in My name, He will teach you all things…” (John 14:26 NKJ)
When Jesus returned to Heaven He said it was better for us that He leave so He could send the Holy Spirit who would teach us, guide us, help us, and write the laws of God on our hearts (John 16:17, Jeremiah 31:33). Our heart is not the thing that pumps our blood, it is what we cannot live without, our spirit. This is the breath of God which is our eternal being.