How do we know that afflictions are beneficial for believers?

The Apostle Peter affirms this concept in 1 Peter 1:6-7, where he writes, 'if need be, you are in heaviness through manifold temptations, that the trial of your faith, being much more precious than gold that perisheth, might be found under the praise and honor and glory at the appearing of Jesus Christ.' Such trials prove the genuineness of faith and are used by God to purify and strengthen His children. Through these experiences, believers can gain assurance of their standing in Christ and become more rooted in their hope and trust in Him.