He is Present, and He isn't Silent
God is quite capable of communicating with His rational creatures. He made the universe, and is present in all its dimensions, from the very large to the very small. One can see His signature on every creature at every level of being. Scientists and mathematicians discover and describe nature's operations in often complicated equations. But only God can set the equations on fire.
Religions and their practitioners fill the world. Atheists are but a planetary minority, gifted with a disproportionate, loud voice. A lot of these religions hold lofty and practical teachings worthy of study. Many of their practitioners are sincere, a few are zealous. Many are exemplary and others, fanatical. It's the same with us.
What is good and true in these religions show us how God's Word was and is the life and light of all peoples (John 1:4). They show...
... that what the law requires is written on their hearts, to which their own conscience also bears witness; and their conflicting thoughts will accuse or perhaps excuse them. (Romans 2:15, NRSVCE).
Belief and Obedience as a Personal Exodus
Even so, God chose to speak and on late human protohistory, He chose Abraham as the first recipient of His word.
God didn't limit Himself to saying "hello" to Abraham. It's a constant in the Bible that every time God speaks to someone, He also demands an "exodus" from that person. That person must first "go out" and do something.
God told Abraham to leave the land of his fathers and go to another one he didn't yet know (Genesis 12:1). Unlike in Jewish oral tradition, Scripture presents Abraham an already monotheistic believer. Despite his convictions, Abraham had first to go out "from within." He had to abandon his initial common sense and fears and move to obedience and trust. Only when Abraham accomplished that exodus within him, was Abraham ready to obey God.
Every encounter with God demands the same internal "exodus", a "going out" in our intellect and will. These are the marks of a true communication from the Creator.
God Speaks to Us From His Very Inner Self
From hereon the Catholic Christian makes an even bolder claim:
In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things came into being through him, and without him not one thing came into being...No one has ever seen God. It is God the only Son, who is close to the Father’s heart, who has made him known.(John 1:1-3; 14; 18, NRSVCE)
This is the central Christian claim: we say that God sent His Word (Gk. λόγος logos) from His inmost being to save us (John 3:16). From eternity His Word became human in time. This Word is no mere part of speech, but God's inmost mind, reason, teaching, and law. The Word who is God (John 1:1) and who fills the whole of creation, became human in Jesus of Nazareth, a First Century Jewish man.
In fact, God became man without ceasing to be God. An otherwise ineffable God for whom no human, linguistic, semantic predicate could apply, became intelligible to us in the Person of Jesus Christ, the Word enfleshed. God became understandable to us in the humanity of Jesus, since the words and deeds of the man Jesus were also the words and deeds of God Himself.
This is why I Chose Theology Over Physics
In Jesus, God spoke to me. He bid me to set forth. He asked me to take a stand for or against Him. I saw the vastness of the universe without and within, and answered the question. From the depths of outer space to the abyss of inner space, He is there. He, the Word, made a word out of me, and uttered me forth. There was no loftier and deserving subject to dedicate my mind, my gifts, my soul, my will, to study God in Christ and all His works. That's why I moved from study of the how of things (physics) to the why of things (theology).
I trusted God would take care of the rest, which He has done in spades. I wasn't too ready for his testing my faith, which He has and continues to do. An untested faith is a child's faith. One must exercise an adult faith and go forth to wherever God appoints.
Things would soon take me into a wide detour, as we will see.
Amen! Let us all "go out from within" and discover the true Christ!!