Why do we have to go through this suffering? For the same reason that Christ did. Verse 10 gives the answer, "that I may know Him." In what way? By the experiences of going through the same kinds of sufferings He went through. We gain intimate knowledge of what it took for Him to do what He did even though our tests, trials, and sufferings are considerably toned down so that we can bear them. It is almost as if we are given a little taste of walking in His shoes.
That is why we are here and that is why we suffer. There is very good reason why we have to go through it. If we do not, we do not really know Christ. He Himself says in John 17:3 that eternal life is to know God.
John W. Ritenbaugh
Wilderness Wandering (Part Five)
The faith through which we please God and receive salvation is God's gift (I Corinthians 12:4, 9). Those in His true church have the faith of Jesus. It is not just our faith in Him, but His faith placed in us. Faithfulness, therefore, is a gift of God produced through the Holy Spirit.
Martin G. Collins
At times, the Bible uses "to know" as a euphemism for sexual intimacy. Paul is not saying here that he desires sexual intimacy with Christ, but that he greatly desires spiritual intimacy with Him. He wants to be so close to Him that he experiences the same level of life as Jesus did—even to the point of suffering or dying as He died, if that is necessary to be made like Him in every possible way. He desires to glorify God in every aspect of his life just as Jesus did (John 17:4).
To achieve this requires a clear vision of where one wants his life to go; dogged, disciplined determination to work toward that end; rigid concentration to avoid becoming distracted; and an unflagging willingness to pay whatever price might be required.
John W. Ritenbaugh
The Offerings of Leviticus (Part Nine): Conclusion (Part Two)
Other Forerunner Commentary entries containing Philippians 3:9:
1 John 4:17