I Cor. 2:14 But people who aren't Christians can't understand these truths from God's Spirit. It all sounds foolish to them because only those who have the Spirit can understand what the Spirit means.
We need to understand this fundamental truth; the people of the world do not understand the things of God. They think faith is foolish; they think living by godly standards is foolishness. They don't understand the things people of faith take for granted. They don't understand the words we use. Those who have very little, if any, experience in church life are quick to dismiss any talk of faith and even become hostile towards it.
We must learn this lesson of truth because we must be careful about how we present Christ to the world. We will generally be far more effective in our witness with how we live than with what we say. The world can easily tune out what we say, but it is much harder to tune out the good we do through Christ.
When we show others that the Gospel really works in practical ways in life, we have a much better chance of being heard. People want practical solutions to life's issues that work, not pat answers. They will pay attention to the difference Christ makes in our living. They can deny the validity of what we say, but they can't deny the validity of seeing it work in us.
We understand the things of God because the Holy Spirit guides us into all truth and helps us to understand. He is constantly giving us more understanding as we are able to absorb it. He teaches us the things we need to know for life. And, when the lost come to know Christ, they too will be led and fed by the Spirit. Until then, don't expect the world to get it, because they won't.