Christian or not, we've all been exposed to the images of a cross. Whether it's the "Old Rugged Cross" or simply a picture of a cross on a hill, we all know what a cross looks like. Think about that cross for a moment. Think about how it is constructed. Now think about the horizontal part of the cross, the part that goes left to right or east to west. Now think about the relationships in your life. Your relationships with the people who matter: your spouse, your friends, your family, your co-workers. Those are the "horizontal" relationships around you, the people you interact with as you go through your life. The people who are within your sphere of influence.
Now think about your relationship with God. No matter where you stand on this Jesus, God, "religion" thing, everyone has a relationship with God. Where we are in that relationship is truly up to us. HE does not move, it is we who grow nearer or further from Him.
Understanding that, think of your relationship with God. The way you talk, pray, seek to know Him, look to Him for guidance and steps of obedience; this is your "vertical" relationship with Him. Your understanding (however that might look for you) that God is with us.
Imagine for a moment that the cross on the hill is suddenly without the vertical portion. What happens to the horizontal part of the cross? It crashes to the ground, right?
Vertical affects Horizontal Relationships
The same can be said of your horizontal relationships (the people around you) when your vertical relationship (with God) is not in place or is wavering. All of your earthly relationships, whether you know it or acknowledge it, are held up or let down by the condition of your vertical relationship with God.
If your relationship with God is not in the right place, all of the relationships with the people in your life will be affected or fall. All of them.
Remember what Jesus said just before He gave up His life on the cross? "It is finished." Scholars and theologians have examined and unpacked what He said in that moment for centuries, trying to understand what Jesus truly meant.
Here's my two cents: the work that was finished on the cross at Calvary? It was the work of Him always being with us; when we submit to Christ as our Lord, the Holy Spirit is always in us. He dwells within us so that the vertical relationship is always secure. THAT'S the work that was finished. THAT'S the miracle of the cross. THAT'S the reason He came and the reason we can celebrate.
If you find your horizontal relationships strained, take the time to examine your own vertical relationship.