I Thessalonians 5:18 In everything give thanks: for this is the will of God in Christ Jesus concerning you.

Notice in this verse how it says to be thankful in everything and not for everything. Evil doesn’t come from God and so we should not thank God for it. But when evil strikes, we can still be thankful for God’s presence and for the good He will accomplish through our distress.

Thanking God in difficulties and stormy circumstances is telling Him that we trust He will safely bring us to shore. God will always bring good out of any bad situation.