I believe the answer is a deeply intimate one ... He lives in the child of God through the presence of the Holy Spirit.
The Creator Almighty, All-knowing, everywhere-present God walked with Adam and Eve in close friendship with thier Maker. Then Satan came into the couple's lives and DESTROYED the close walk they had with God by enticing them to disobey God. Satan being a DECEIVER did to Adam and Eve what he knew best to do, He tricked them into believing that by eating the forbidden fruit they could BE LIKE Almighty God. The result of thier action was that they had to flee from the presence of God in shame. Thus there ceased the one-on-one communication with God. As sinners no human being can get close to God the same way that our first parents did. Almighty God IS infinitely Holy and nothing sinful is allowed in His presence. Now God devised a remedy for this situation. He Himself put on flesh as the baby Jesus Christ and grew up among sinful human beings and in due course He taught mankind how to live lives that could come as CLOSE AS POSSIBLE to the Creator God. The fellowship of mankind with God was restored so mankind is able to talk with God, not physically as Adam and Eve did, but Spiritually. That's why we are required to talk to God (pray) in Spirit and Truth. Jesus Christ, Almighty God in human flesh left Earth to live in heaven with the Father, but He sent a Substitute, the Holy Spirt to Earth so that mankind can communicate with Almighty God thru' the Holy Spirit. Since God is not on Earth to talk with us, He gave His WORDS in written form and we call it the Holy Bible. Now our "one-on-one" communication is back with/to us. When we read the WORDS God wrote (aka the Holy Bible), we are listening to Him. When we pray in SPIRIT and TRUTH, we are talking to Him. If we don't "talk" to Him in truth, please DO NOT expect to be heard. This is where true FAITH comes in. A person who is BORN AGAIN as in John 3:3 will have the privilege of being heard by Almighty God, aka Jesus Christ or Holy Spirit. If you are not born again and you are talking to God in prayer, forget it. Why? Because He will not hear. But there is another god who will hear and that is Satan. Satan is called the "god of this world" in 2nd Cor. 4:4. He will answer the prayers of those who are not in right fellowship (relationship) with Almighty God. Now here;s a HUGE problem. Those who pray, not in truth and spirit, THINK that they are praying to the Father-God in heaven When they get thier prayers answered, if they do get answered, these COIN believers i.e Chritian Only In Name, people think that the Father in Heaven answered. This way Satan is able to keep the COIN people happy in thier COIN state. Why should they get born again if thier needs are met thru' thier prayers. Let me illustrate: A woman bought a lottery ticket and placed it at the foot of a statue of Mary. She won. Now, will that woman ever deviate from worshipping at the foot of Mary? Unless the Holy Spirit SHOWS her the WAY to everlasting life in heaven with the Lord Jesus Christ, she will never even consider stopping her prayers to Mary.