Real faith proves itself by its staying power. The more it is tested, the stronger it gets. This is because its source is God. Faith takes us beyond our natural abilities and resources and taps into God’s strength and character. Faith never collapses under stress because it is rooted in God’s faithfulnesss. If our faith fails, it is because it was not the real thing.

There is a famous doctrine of the Reformation called the Perseverance of the Saints. This doctrine has been corrupted into a much maligned phrase – “once saved always saved.” But this is not what the original doctrine meant. The perseverance of the saints teaches that those who have real faith will be enabled by God to persevere or remain faithful to God to the end. Another way of stating this is real faith never fails. This doctrine gives the follower of Christ great confidence during severe testing.

We know God has not left us to our own resources. His Spirit, the Spirit of faith, dwells within each child of God, giving him or her God’s strength.

Jesus prayed for his beloved disciple Peter on the eve of his crucifixion, asking his Father to enable Peter persevere through the coming severe test of his allegiance to Christ.

“Simon, Simon, behold, Satan demanded to have you, that he might sift you like wheat, 32  but I have prayed for you that your faith may not fail. And when you have turned again, strengthen your brothers.” Luke 22:31-32 (ESV)  

Peter denied his Lord three times that night, but his faith never failed. We know this because he immediately repented and kept following the Lord, being eventually restored after Christ’s resurrection. Peter came to an end of his own ability to endure, but the faith of God that resided in him persevered. Peter never stopped following his Master all the way to the end when he was crucified upside down for his allegiance to his Lord.

We may fail to follow God completely at different times in our lives, but, if real faith resides in us, we will hang in there and keep following Jesus.

In contrast, Judas not only denied and betrayed Jesus, he also committed suicide because he had no faith that he could be restored. Whatever motivated him to follow Jesus eventually withered away, leaving him to his own resources, which were insufficient for the test. Only real faith that is rooted in God has the power to persevere.

I have been crucified with Christ,[59] and it is no longer I who live, but Christ lives in me. So[60] the life I now live in the body,[61] I live because of the faithfulness of the Son of God,[62] who loved me and gave himself for me. Galatians 2:20 (NET1) 

Our ability to be faithful comes directly from Christ’s own faithfulness. His faith has become our faith through the agency of the Spirit of God who indwells us.

God allows life to bring us into many difficult situations and tests. We might think of our earthly life as a proving ground of our devotion to God. Adam and Eve denied the Lord in the Garden. We have the opportunity to be faithful to our Creator, whatever he may require us face. The more difficult the test, the greater the glory God receives from our perseverance.

Blessed be the God and Father of our Lord Jesus Christ! According to his great mercy, he has caused us to be born again to a living hope through the resurrection of Jesus Christ from the dead, 4  to an inheritance that is imperishable, undefiled, and unfading, kept in heaven for you, 5  who by God’s power are being guarded through faith for a salvation ready to be revealed in the last time. 6  In this you rejoice, though now for a little while, if necessary, you have been grieved by various trials, 7  so that the tested genuineness of your faith—more precious than gold that perishes though it is tested by fire—may be found to result in praise and glory and honor at the revelation of Jesus Christ. 8  Though you have not seen him, you love him. Though you do not now see him, you believe in him and rejoice with joy that is inexpressible and filled with glory, 9  obtaining the outcome of your faith, the salvation of your souls. 1 Peter 1:3-9 (ESV)  

Faith responds with praise and worship when it is tested.

Our natural self does not. The earthly part of us always wants to enjoy comfort and ease and complains about any discomfort. When we face tests and temptations, it is important for us to tap into our spirit person, where faith resides. When we do this, we are able to count every test as an opportunity to be faithful to our Creator – Redeemer – Sustainer, our Lord Jesus the Messiah King of Israel.

Count it all joy, my brothers, when you meet trials of various kinds, 3  for you know that the testing of your faith produces steadfastness. 4  And let steadfastness have its full effect, that you may be perfect and complete, lacking in nothing. James 1:2-4 (ESV)