“In everything give thanks; for this is God’s will for you in Christ Jesus.”
1 Thessalonians 5:18

As we see in our opening verse this is God’s will, but we need to see verses 16 and 17 as well.
“Rejoice always, Vs. 16
Pray without ceasing. Vs. 17
In everything give thanks…”  Vs. 18

There is not a time or circumstance where we are not to be thankful.  Looking closely, we recognize that giving thanks keeps us aware of God’s presence.  It reminds us that He is with us in every situation and circumstance, not only the good things, but hard things as well.  It is in coming to know the reality of Romans 8:28 that our trust in Omnipotent God is firmly rooted.

“And we know that God causes all things to work together for good to those who love God, to those who are called according to His purpose.”

This being so, the command ‘in everything give thanks’ becomes the natural response to all that happens in our lives.

In looking closely, we also see that this is not just a lip service of thanks, but it is to come from an attitude of rejoicing and an attentiveness to prayer.  
In Philippians 4, Scripture tells us,
“Rejoice in the Lord always; and again I will say rejoice!”  Vs. 4
“Be anxious for nothing, but in everything by prayer and supplication with thanksgiving let your requests be made known to God.”  Vs.6
And the results?
“And the peace of God, which surpasses all comprehension, shall guard your hearts and minds in Christ Jesus.”  Vs. 7

These verses in Romans and Philippians indicate trials and testing.  They are inevitable!  They are for our good, for our establishment in Christ and we have the assurance that,
“No temptation has overtaken you but such as is common to man; and God is faithful who will not allow you to be tempted beyond what you are able but with the temptation will provide the way of escape also, that you will be able to endure it.”  1 Corinthians 10:13

What is the purpose?
“For momentary, light affliction is producing for us an eternal weight of glory far beyond all comparison, while we look not at the things which are seen, but at the things which are not seen, for the things which are seen are temporal, but the things which are not seen are eternal.”  2 Corinthians 4:17-18

So let us be thankful as we are exhorted to do:
“Enter His gates with thanksgiving.
And into His courts with praise.
Be thankful to Him, bless His name.
For the LORD is good;
His mercy is everlasting.”  Psalm 100:4-5

“And whatever you do in word or deed, do all in the name of the Lord Jesus, giving thanks through Him to God the Father.”  Colossians 3:17

With grateful hearts we praise, honor and give glory to Father, Son and Holy Spirit.  Amen