Jer 31:33, Jn 14:26, Jn 15:26, Jn 16:13-14, 1 Cor 2:12, Heb 8:11, 1 Jn 2:20
In the Old Testament it was foretold that God would write His law in our hearts. (Jeremiah 31:33)
Jeremiah 31:33 But this shall be the covenant that I will make with the house of Israel; After those days, saith the Lord, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people.
When the Holy Spirit, whom God and Jesus Christ will send, come upon us, he will teach us everything. In particular, the Holy Spirit makes us realize that Jesus is the Christ. (1 John 2:27, John 14:26, John 16:13-14, 1 Corinthians 2:12, 1 John 2:20)
1 John 2:27 ut the anointing which ye have received of him abideth in you, and ye need not that any man teach you: but as the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you, ye shall abide in him.
John 14:26 But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
John 16:13 Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come. 14 He shall glorify me: for he shall receive of mine, and shall shew it unto you.
1 Corinthians 2:12 Now we have received, not the spirit of the world, but the spirit which is of God; that we might know the things that are freely given to us of God.
1 John 2:20 But ye have an unction from the Holy One, and ye know all things.