Here's the d'var Torah I wrote for this week's Torah portion back in 2006 for Radical Torah.
When Moses had finished the work the cloud covered the Tent of Meeting, and the Presence of the Lord filled the Tabernacle. Moses could not enter the Tent of Meeting, because the cloud had settled upon it and the Presence of the Lord filled the Tabernacle. When the cloud lifted from the Tabernacle, the Israelites would set out, on their various journeys; but if the cloud did not lift, they would not set out until such time as it did lift. For over the Tabernacle a cloud of the Lord rested by day, and fire would appear in it by night, in the view of all the house of Israel throughout their journeys.
The ancient Israelites saw clear signs of God: in the pillar of cloud and fire that guided them out of Mitzrayim and protected them from the advancing Egyptian army; in the dense cloud of smoke and fire upon Mount Sinai at the moment of the revelation of Torah; and in the cloud which rested over the Tabernacle, indicating God's presence among them.
The cloud showed the Israelites where to wander. The geographical distance between the place they left and the place they were going toward isn't so great; why take forty years to travel so short a way? Because the route God led them on was roundabout. Slavery damages not only the body but also the soul, and that kind of constriction lingers in the heart. God knew it would take the Israelites forty years to learn another way of being.
It must have been frightening, at first, being free. After a lifetime of unquestioned allegiance to Pharaoh, choosing allegiance to the Source of all Being must have seemed like an unimaginable leap of faith. Fortunately, though their new God was beyond comprehension and beyond human sight (even Moses was only permitted a glimpse of the Divine backside, and came away irradiated and glowing with holiness as a result), the Israelites knew their mysterious God was with them -- thanks to the divine cloud. In those days, it was easy to know when God wanted the community to stay put, and when God wanted the community to move. It was easy to recognize God's presence in the plume of smoke by day, the fireworks by night.
Today we, too, strive to create our lives so that the Source of All that Is will dwell among us. But we don't have the luxury of seeing God's presence. We have no cloud of smoke or nightly fire. Like our ancestors -- freed from lives of constriction into lives of wide-open possibility -- as we mature we too are continually freed into the occasionally terrifying freefall of our spiritual lives. Our ancestors had to broaden their understanding of God from something they could touch (the Golden Calf) to something they could sense but not directly encounter (the cloud over the Mishkan). We are called to broaden that understanding even further: from something intangible but perceptible to something omnipresent but beyond our ken. We are asked to free ourselves even from dependence on physical manifestations of holy Presence.
How do we know when God is among us? How do we know when to stay encamped, and when to pick up stakes and keep moving? Sometimes we don't, and we have to learn to do the best we can anyway. We have to believe that our journeying has a destination, even when we can't see the pillar of smoke leading us from hither to yon. If we find that our lives map to a roundabout route, we owe it to our Source to trust that the divagations have a purpose.
It's easy to look back at the past chronicled in Exodus and to wish for the kind of visible relationship with God our ancestors knew. To long for a cloud of smoke and fire to lead us in our wandering through the wilderness of modern life. But I think that's an impulse we need to resist. When the ancient Israelites looked back longingly at the bread and meat of Egypt, their rearview-mirror mindset blinded them to the wonder of the manna falling from heaven for their consumption. When we wish for what was, we risk losing sight of what is – and we do a disservice to the way God is manifesting in our lives right now.
Avadim hayinu; ata b'nei chorin. We were slaves, but now are free -- and one of the obligations of that freedom is to relish, or at least to meet, the challenges it places before us. Challenges like growing in our understanding of God. Once upon a time, we connected with God by making sacrifices on the altar the Torah so lovingly describes; now we connect with God through prayer. Once upon a time we built a home for the Presence with linen, brilliant threads, and hammered gold; now we build a home for the Presence with the everyday actions of our lives. Once upon a time we saw the Divine in a cloud of smoke and fire; now we must learn to sense the Divine in the passage of time. When Moses asked Who instructed him to begin the process of the Exodus, God answered "Ehyeh Asher Ehyeh" -- I Will Be Who I Will Be. God is continually unfolding as something new. As a holy people, we must do the same.