Mat 5:17 Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil.
Mat 5:18 For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.
When Jesus came he kept all the laws and in him were many prophecies fulfilled. When he returns again all the prophesies shall be fulfilled.
Jesus met on the mountain with Moses, representing the law and with Elias or Elijah, who represented the prophets.
Mat 17:5 While he yet spake, behold, a bright cloud overshadowed them: and behold a voice out of the cloud, which said, This is my beloved Son, in whom I am well pleased; hear ye him.
Mat 17:6 And when the disciples heard it, they fell on their face, and were sore afraid.
Mat 17:7 And Jesus came and touched them, and said, Arise, and be not afraid.
Mat 17:8 And when they had lifted up their eyes, they saw no man, save Jesus only.
God the Father spoke that now we are to hear the Son, he is the living embodiment of the word of God. Christ the Word, eternal in Spirit, hear him.
In another story the rich man in Hades called out to Lazarus the beggar who was with Abraham in Paradise, he wanted Lazarus to warn his five brothers of the torment in hell.
Luk 16:29 Abraham saith unto him, They have Moses and the prophets; let them hear them.
Luk 16:30 And he said, Nay, father Abraham: but if one went unto them from the dead, they will repent.
Luk 16:31 And he said unto him, If they hear not Moses and the prophets, neither will they be persuaded, though one rose from the dead.
Evangelism is for those living on earth. We are called to warn the people not by law but by faith and God's grace and to bring them to Jesus who is risen from the dead. Jesus fulfilled the law, in him is the fulfillment and now we are under the New Covenant of salvation by faith, with the laws written on our hearts by the Holy Spirit. The Holy Spirit speaks not of himself, so we are not to exalt ourselves and call it His Spirit.
Joh 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.
The LORD Jesus Christ is the fulfillment of the law and the indwelling Holy Spirit is the Spirit of prophecy. He will show us all truth.
Col 2:9 For in him dwelleth all the fulness of the Godhead bodily.
Col 2:10 And ye are complete in him, which is the head of all principality and power: