God is never limited by place
People have bodies, so we can only be in one location at a time. God is different. Solomon recognised this when he dedicated the temple in Jerusalem: even the heavens could not contain the God who had chosen to make his name known there (1 Kings 8:27). God may meet people in particular places, but no building, nation, or corner of the universe can hold him.
The word omnipresent is not used in the Bible, but it describes what Scripture teaches about God. He is fully present everywhere. That does not mean God is spread thinly across the world, as though one part of him is here and another part is far away. He is wholly God wherever he is present.
Am I a God at hand, saith the Lord, and not a God afar off? Can any hide himself in secret places that I shall not see him? saith the Lord. Do not I fill heaven and earth? saith the Lord.
There is nowhere beyond his reach
Psalm 139 faces this truth honestly. David considers the highest heavens, the realm of the dead, the dawn, and the farthest sea, then sees that God is already there (Psalm 139:7-10). For David, this was not a cold idea. It meant that even when he could not find his way, God could still lead and hold him.
That can steady someone who feels forgotten, isolated, or far from home. A hospital room, a night shift, a prison cell, a crowded city, and a quiet bedroom are not places where God has stopped being God. You do not need the perfect setting or perfect words before you can turn towards him.
Whither shall I go from thy spirit? or whither shall I flee from thy presence? If I ascend up into heaven, thou art there: if I make my bed in hell, behold, thou art there. If I take the wings of the morning, and dwell in the uttermost parts of the sea; Even there shall thy hand lead me, and thy right hand shall hold me.
God is near, but he is not everything
Omnipresence does not mean that God is identical with trees, oceans, people, or the universe itself. The Bible says God made the world and gives life to those in it, while also remaining Lord over it (Acts 17:24-25). Creation shows his power and care, but creation is not God.
Nor does God's presence mean he approves of everything that happens. Jeremiah speaks of people trying to hide their wrongdoing, and God answers that their hidden actions are still before him (Jeremiah 23:24). His nearness is reassuring for the vulnerable, but it also calls us to honesty. Nothing needs to be concealed from the One who already knows.
A truth for ordinary life
God's presence is not merely an idea for difficult days. Paul told the people of Athens that God is close enough to be sought, and that every moment of human life depends on him (Acts 17:27-28). So prayer is never a message sent into empty space. God is already near before you begin.
Still, feeling God's presence and God actually being present are not the same thing. There may be seasons when prayer feels dry or life feels dark. Psalm 139 does not deny those places. It says they are not outside God's reach. Read that psalm slowly, and bring God the part of your life that currently feels most distant.
That they should seek the Lord, if haply they might feel after him, and find him, though he be not far from every one of us: For in him we live, and move, and have our being; as certain also of your own poets have said, For we are also his offspring.