The presence of God will not keep us from difficulties. That’s evident from Psalm 124.
It also sounds contradictory when you compare it to the assurances of Psalm 121 and 125.
But the psalmists do not live in a fantasy world. Their world is real. They know God is present. They know His protective eye and hand is on them. But they also know life has its struggles, challenges, and yes, even dangers. God’s presence does not exempt them from those. It should they (and we) think. But it doesn’t. Why it doesn’t is not readily apparent. Or ever, really. And so, as they struggle with this conundrum, they write hymns, confident of God’s care, pressing on all the while through valleys of difficulties and over mountains of obstacles. And the fact that they are able to keep moving is testimony to the presence of God.