Why does God save us?
Kaoru Ishikawa was a Japanese master of the quality sciences. He has a particular measurement tool named after him - the Ishikawa Diagram. This simple seven-legged diagram helps us to determine the root cause of a problem or process. It answers the question "Why?" Sometimes folks augment this diagram with another simple tool called the "Five Whys". To figure out why something happened (at the root), one asks the question "Why?" to each response. Usually after five rounds, the root cause surfaces.
For instance, parents use this question often when a child misbehaves. "Why did you do that?" A childlike answer usually follows. As Christians, we all should know that the root cause of all bad behavior is our sin nature. This could logically lead us to a conclusion about how to fix the bad behavior of our children. Get them saved and God will fix them up.
Is that why God saves us? To make us better people? You take a look around and answer that question for yourself. Granted, Jesus indeed saves some folks from their wicked ways. Deliverance from drugs, alcohol, anger, and such is quite common. But these are all effects of salvation. They are not the why.
Many people preach about heaven and hell. Scare children enough with talk about hell and every hand will go up at the salvation invitation. Is that why God saves us? To keep us from hell? While it is true that we escape that certain condemnation, it is nonetheless an effect of salvation.
On the other hand, folks hung up on the "God is love" thing are delighted to go forward at the invitation. Of course they want to go to heaven. Who doesn't? But is our heavenly destiny why God saved us? No. It is an effect.
All these things are wonderful effects of salvation. They are all certain. But they are not the answer to why God saved us. Take a careful look at them again. Notice who the effect is on for each one. Us. What about God? While God is glorified in these effects, the focus is nonetheless on us. What's in it for God?
That is what leads us to the answer of why He saves. That is what leads us to the power of preaching. That is what points us to the single thing which should dominate our minds, speech, and actions. That is the cross of Jesus Christ.
God saves us because Jesus died and shed all His blood. That is what saves us from our sin nature. That is what delivers us from our sins. Nothing but the blood from Calvary.
All other preaching is vain, man-centered, and dangerously leading hearers to no salvation at all. We must learn not to confuse a cleaned-up man with a blood-washed man. The former washes himself in filthy rags while the latter wears the spotless white linens of righteousness in Jesus Christ.