"Rejoice always, pray continuously, and give thanks in all circumstances", 1 Thessalonians 5:16-18. Easy words to follow when life is going our way. But when we are going through a hard time and stress seems to be everywhere, it's a little bit harder to follow through. However, when we believe in God, who is bigger than any circumstance, these verses start to make sense.
After all, joy does not equal happiness. Happiness is circumstantial feeling based on how good our life is. Joy is found only in the Lord. It is the peace and understanding that no matter how hard life gets, you are not alone. God is with you, and with Him comes hope for the future. So we rejoice because He will deliver us from our trials.
Since God is faithful to us, shouldn't we also then be faithful to Him by being devout in our prayer life, and continuously seeking after Him? Matthew 7:7 says, "Ask and it will be given to you; seek and you will find; knock and the door will be opened to you." If you seek after God, you will find Him. Pray with Faith that he is listening; ask unselfishly for His blessings, and He will bless you.
And this, brothers and sisters, is why we give thanks; because He is always there bestowing His blessings upon us. When we seek after God, we will find His favor and rejoice in the hope that He brings. With God, there is always hope. And with hope, comes every reason to give thanks.