One thing modern minds have trouble with is the fact that it takes God so long to bring about the transformation of the human heart. We see the Old Testament where God uses much more brutal tactics to force his way into human society. Humans were much more violent back then and needed God to use violence before they would take him seriously. He did so in way He really does not today. People don't understand. Why could God not just work the way He does today?
It takes time. Sin closes off grace. The more serious the sin the more explicit God's intervention needs to be. As we slowly learn to cooperate with God's grace we receive more and more graces in more gentle ways. Yet it goes very slow. They say the church sees history in centuries while we see it in years.
Yet even in our lives we see the same dynamic. We grow in grace but it happens slowly. Every step is a struggle. It can take years before we make a breakthrough. Again we wonder why it takes so long. If God is almighty then can't He move a little quicker?
This is especially true at lent. We make the same fasts and pray the same prayers year after year. Are we making progress? You really have to look back 10 years before anything becomes obvious. Even when we see that we wonder why we have grown in some area and not in others.
The answer is we need to appreciate just how far we need to go. How big a gap there is between where we were and where God is leading us. If we just changed in an instant we would never get it. We don't really understand the nature of sin until we fight against it and lose. We really don't get how big a deal salvation is. That we are not just made truly good but that such goodness is so far out of our reach. That we don't just need a little help from God. We need to become more and more dependent on Him. We need to invite Him into places we could not imagine when we started our journey.
The other dimension to this is freedom. God can't just ask us to choose heaven or hell. That would not make any sense. Like in the movie the Matrix. There was a choice given to the main character but he didn't really understand that choice because at that point he was still mostly ignorant of what was involved. God does not give us choices like that even if it sometimes feels like it. The choices are between taking the next step down the road to heave or the next step down the road to hell. It is a choice we can understand. We can feel the pull towards good and the pull towards evil. We have the real possibility of going either direction.
How long does it take before the allure of evil stops being attractive to us? Some sins lose their attraction but there is always something deeper. Every step seems so slow. When you try and explain it to a non-Christian it becomes hard. It is not logical. We trust God so far and then we are afraid to take the next step. Why is it so hard? It is very personal ground we are talking about. It takes time for us to get comfortable with the intimacy.
So the victory of the cross is slow just like the crucifixion was slow. God could be more efficient. He just wants us to see salvation in all it's gory detail. He ants us to feel it and He wants us to choose it knowing all that.