again, Paul was speaking to born again believers ... so we're talking about folks who have already come to faith the Lord Jesus Christ.
In Phil 1:29, Paul speaks of those who suffer for Christ's sake and he tells the believers that God will supply all that is needed in order for the believer to stand and withstand in time of suffering. This is a great and precious promise to the believer.
I believe God strengthens faith within believers who suffer on behalf of the Lord Jesus Christ. God works within to make perfect, establish, strengthen, settle the believer who is going through times of trial or suffering (1 Peter 5:10).
Do you believe God has to "give" faith to those to who are already born again?
There's a record in Acts 5 when the apostles were imprisoned and beaten because they taught in the temple ... when they were released, they departed from the presence of the council, rejoicing that they were counted worthy to suffer shame for his name (Acts 5:41) and they were daily in the temple, and in every house, they ceased not to teach and preach Jesus Christ (Acts 5:42).
You think the apostles relied on their own strength/capability? No, God sustained them ... God strengthened their faith ... God caused them to rejoice in the midst of adversity.
That truth is revealed in Philippians 1:29 For unto you it is given in the behalf of Christ, not only to believe on him, but also to suffer for his sake
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