The verses in John 14:1-31 took place the night before Jesus was crucified. He told His disciples he would be leaving to go to the Father. The disciples were afraid, but he spoke these words to comfort them, and to comfort us in times of trouble and fear.
When in times of fear, we have to remember the Lord's promise. That He has gone to prepare a place for us, and when everything is ready, He will come back and get His children. Life can be a series of problems or storms, some of which can be terrifying, but if we have Jesus, He will calm our fears.
We should always remember the Lord's purpose. Often times in fear, we want more confirmation from God, but He is not in the business of explaining (why He does things), but of sustaining us. He does not owe us an explanation for anything, and although it is ok to ask "why", it is more important to have faith and trust the He knows the answer.
We have to remember that the Lord is present in our times of need. If we trust in Him, the Holy Spirit lives in us and will comfort us. That peace is not based on our circumstances. It is there whether we are healthy or sick; rich or poor.
Jesus deserves not only our obedience, but also our trust.
There is a way that seems right to a man, but its end is the way of death. Proverbs 16:25
I am the way, the truth, and the life. No one comes to the Father, except through me. John 14:6