The reason why people cannot see or hear God is because of sin. Sin separates you from God. You need to have your sin removed from you before you can come into the presence of the living God. How do we do that?
You REPENT from sin, you TURN AWAY FROM SIN and you plead Jesus Christ forgiveness with remorse and sorrow and you plead Him to remove the guilt of your sin and to accept you as a child of God. If you cry out to Jesus from your heart and you are serious and you remove your idols and your sin from you then you will come into His presence, you will experience the presence of the LIVING GOD, Jesus Christ, but then you have to have your sins washed off through water baptism.
Once you have been baptized in water for the washing off of your sin you can ask Jesus Christ for the Holy Spirit that He promised to those who have repented and who have been baptized in water. He will fill you with His Spirit, with His presence and you will experience His presence, you will HEAR Him, you will SEE Him, you will experience Him IF you keep yourself HOLY and DEVOTED to Him.
Without HOLINESS no man shall see the Lord. Only those who are PURE IN HEART will see God. It is only when your heart is pure and you live in utter holiness and obedience that you can experience the presence of God. When you have received the Holy Spirit that dwells inside of you and you HEAR the Master's voice CLEARLY, you have to deny yourself every day, pick up your cross and live in utter holiness and obedience to Him and then you will experience Him, you will SEE the kingdom of God and you will KNOW the KING Himself.
Those who sin do not know Him and they have not seen Him. If you want to SEE GOD and HEAR GOD, get rid of your sin and BE HOLY.
May Jesus bless you.