"Be joyful (rejoicing) in hope, patient in affliction (tribulation), faithful (steadfast) in prayer." Romans 12:12

Jesus tells His disciples,
"These things I have spoken to you, that in Me you may have peace. In the world you will have tribulations; but be of good cheer, I have overcome the world." John 16:33

The Greek word here is THLIPSIS. "Vine's Expository Dictionary of Old and New Testament Words" says it, 'primarily means a pressing, pressure, anything which burdens the spirit.'
"Strong's Exhaustive Concordance of the Bible lists these words: anguish, burdened, persecution, tribulation, trouble.

'Patient in affliction (tribulation)'
"My brethren, count it all joy when you fall into various trials, knowing that the testing of your faith produces patience." James 1:2-3 (Notice James said, 'when' not 'if')

In the Believer's life affliction is--
A means of testing:
Jesus is explaining to His disciples the parable of the soil and seed. Read Vs. 2-20 for the full picture.) "And they (word) have no root in themselves, and so endure only for a time. Afterwards when tribulation or persecution arises for the word's sake, immediately they stumble." Mark 4:17

They are to be endured:
Paul to Timothy and to us as we minister to others, "But you be watchful in all things, endure afflictions, do the work of an evangelist, fulfill your ministry." 2 Timothy 4:5 Paul is telling Timothy (and it is even happening now in some churches) that a time will come when people will not endure sound doctrine, but will follow their own desires because they have itchy ears and they will turn their ears away from the truth. Read Vs. 3-4

It is part of the gospel as Paul writes to the Thessalonians, "For our gospel did not come to you in words only, but also in power, and in the Holy Spirit...And you became followers of us and of the Lord, having received the word in much affliction, with joy of the Holy Spirit.
1 Thessalonians 1:5-6

Believers are not to be shaken by afflictions:
Paul had sent Timothy to the Thessalonians to establish and encourage them concerning their faith, "That no one should be shaken by these afflictions; for you yourselves know that we are appointed to this. For, in fact we told you before when we were with you we would suffer tribulations, just as it happened, and you know."
1 Thessalonians 3:3-4

The afflictions are momentary when we think in terms of eternity:
"For our light affliction, which is but a moment, is working for us a far more exceeding and eternal weight of glory." 2 Corinthians 4:17

We have God's promise of deliverance from afflictions:
David speaks from experience in Psalm 34:19, "Many are the afflictions of the righteous, But the LORD delivers him out of them all."

Tribulations and afflictions can not separate us from God in Christ!:
We have in Romans 8:35-39 that wonderful declaration of assurance and victory, (Read the five verses.) "Who shall separate us from the love of Christ? Shall tribulation, or distress, or persecution, or famine , or nakedness, or peril, or sword?...
For I am persuaded that neither death nor life, nor angels nor principalities nor powers, nor things present nor things to come, nor height nor depth, nor any other created thing, shall be able to separate us from the love of God which is in Christ Jesus our Lord." Vs. 35; 38-39

There is so much more but I close with Romans 5:3-5 "...We also glory in tribulations, knowing that tribulation produces perseverance; and perseverance, character, and character, hope. Now hope does not disappoint."

Thank you Lord for the trials, afflictions, tests for they are working in us a greater faith as we patiently look to Christ in all things. "And we know that all things work together for good to those who love God, to those who
are the called according to His purpose. "   Amen