Is 40:29 says of the Lord that he giveth power to the faint. He can do this because he never faints [Is 40:28]. The Lord assures us that we are going to be faint. But instead of encouraging us to pull ourselves up by our boot straps, the Lord gives us the power we need in the times we are faint.
He giveth power to the faint to:
Renew your strength – Is 40:31 – but you must wait upon the Lord – otherwise you will expend your strength and give up – by waiting for his power you will be able to walk, run and even fly.
Keep doing well – Gal 6:9 – but you must not get weary and quit – you must keep on doing well in his power – by working in his power you will reap in the due season.
Endure chastening – Heb 12:5-11 – but you must not despise the Lord or turn away from his rebukes – you must rely upon his power to get through it – by enduring chastening in his power you will be blessed with his holiness and the peaceable fruit of righteousness.
Continually pray – Lk 18:1 – but you must continue to have faith – you can’t quit just because he hasn’t answered – by praying according to his power you will be blessed in time with answers to your prayers.
Fight your enemies – Jud 8:4 – but you must keep pursuing them – you cannot surrender – by his power if you keep fighting your enemies you will defeat them.
Suffer – Job 4:5 – you must humble yourself and trust God – you can’t get mad at God or become bitter or turn to sin – by his power if you suffer he will make you perfect, stablish, strengthen, settle you [1 Pet 5:10], glorify you [Rom 8:17] and let you reign with him [2 Tim 2:12].
Be saved – Ps 119:81 – you must hope in his word – you can’t trust any other power besides the Lord Jesus Christ – when you are saved by his power you are blessed with his supernatural power now and with his eternal life forever.
Conclusion: The key to all of these is: first, to recognize that you don’t have the personal strength to do any of these on your own; second, to recognize that the power to do them is in Jesus Christ; third, to recognize that there are conditions in every case that must be met in order to avail yourself of his power; and fourth, to recognize that if you will rely upon his power and not faint there are supernatural blessings that will cause you to thank God for the trouble you had to experience in order to realize your need of the Lord’s power.