God has spoken to mankind over the centuries in many different ways, and in these last days He has given specific instructions.
God, after He spoke long ago to the fathers in the prophets in many portions and in many ways,  in these last days has spoken to us in His Son, whom He appointed heir of all things, through whom also He made the world.
Heb. 1:1-2 (emphasis added)
And then again,
Six days later Jesus took with Him Peter and James a and John his brother, and led them up on a high mountain by themselves.  And He was transfigured before them; and His face shone like the sun, and His garments became as white as light.  And behold, Moses and Elijah appeared to them, talking with Him.  Peter said to Jesus, “Lord, it is good for us to be here; if You wish, I will make three tabernacles here, one for You, and one for Moses, and one for Elijah.”  While he was still speaking, a bright cloud overshadowed them, and behold, a voice out of the cloud said, “This is My beloved Son, with whom I am well-pleased; listen to Him!”
Matt 17:1-5 (emphasis added)
That is pretty plain, is it not? God, the Father, has spoken to us through His Beloved Son, Jesus. By reading the Bible we can find out what He said. If someone claims to speak for Him, it will line up with what Jesus said. If it does not, the person is not speaking for God.
Thank you, God, for making it so simple!
No secret societies, no rituals, special prayer methods, magic words, secret oaths or mystic ceremonies. Just read what Jesus said in the Bible to know what God has said.