All we swear, this is the common slang that you have to push us in God. It's not just an ordinary slang, but that's the declaration of faith.
The Bible says that as we believe, we also speak. We speak because it is by the word of God. We speak because we know that God has declared. What God has declared for us will surely come to pass.
Whatever God has done or ordained concerning our life will not come to pass if it does not speak. Doubt and anxiety come when we allow the problem of life to enter into us and not meditate on the word of God. When we set our faith and look upon the challenge that we are going through, we will be filled with worries and anxiety.
Worries and anxiety can be very dangerous. Many people have committed suicide because they have so many worries and anxiety. But when we put our trust in the word of God, that is the only criteria that should make us to have peace. We need the peace of God. We should only rely upon that word of God, if not. We might lose faith in him.