There was once a big turntable bridge, which spanned a large river. During most of the day, the bridge sat with the length running up and down the river parallel with the banks, allowing ships to pass freely on both sides of the bridge. But, at certain times of the day, a certain train would come along and the bridge would be turned sideways across the river allowing the train to cross. A switchman sat in a small shack on one side of the river, where he operated the controls to turn the bridge and lock it into place when the train crossed.
One evening, when the switchman was waiting for the last train of the day to come, he looked off into the distance, through the dimming twilight, and caught sight of the train's light. He stepped to the controls and waited until the train was at a prescribed distance when he was to turn the bridge. He turned the bridge into position, but to his horror, he found that the locking control didn't work. If the bridge was not locked securely into position, it would wobble back and forth at the ends when the train came to it, causing the train to jump the track and go crashing into the river. This would be a passenger train with many people aboard. He left the shack with the bridge turned across the river, and hurried to the other side of the river, where there was a lever, which he could use to operate the lock manually. He could hear the rumble of the train now, and leaned backwards to apply his weight to it, locking the bridge. Many lives depended upon this man's strength.
Then, coming across the bridge from the other direction, he heard a sound that made his blood run cold. "Daddy, where are you?" His four-year-old son was crossing the bridge to look for him. His first instinct was to cry out to the child, "Run! Run!" But the train was too close. The tiny feet would never make it across the bridge in time. The man almost left the lever to run and snatch up his son and carry him to safety, but he realized he could not get back to the lever in time. Either the people on the train, or his son, must die. He took just a moment to make his decision.
The train sped swiftly and safely on its way, and no one on board was even aware of the tiny, broken body thrown mercilessly into the river by the rushing train. Nor were they aware of the pitiful figure of a sobbing man, still clinging tightly to the locking lever long after the train had passed. They didn't see him walking home more slowly than he had ever walked to tell his wife how he had sacrificed their son.
Now, if you can comprehend the emotions, which went through this man's heart, you can begin to understand the feelings of our Heavenly Father, when He sacrificed His Son to bridge the gap between us, and eternal life. Can there be any wonder that he caused the earth to tremble and the skies to darken when His Son died? And how does it feel when we speed along in life without giving a thought to what was done for us through Jesus Christ? When was the last time you thanked Him for the sacrifice of His Son? - Author Unknown