There is no more, or no less to it.
What saves the lost is FAITH in the Word of the Lord Jesus Christ;
What restores life is FAITH in the Word of the Lord Jesus Christ;
What transforms a ruined life is FAITH in the Word of the Lord Jesus Christ!
What makes a person righteous and worthy before God is FAITH in the Word of the Lord Jesus Christ;
What heals is FAITH in the Word of the Lord Jesus Christ.

But without faith it is impossible to please Him, for he who comes to God must believe that He is, and that He is a rewarder of those who diligently seek Him. Hebrews 11.6
Therefore, whatever doubt may exist is already a reason for condemnation, because it is a sin. Even when it comes to food, if there is doubt in what you eat, then there is sin (there is condemnation). EVERYTHING THAT IS NOT BY FAITH IS SIN, this is, it is reprehensible. We conclude that, whatever it may be, doubt is of the devil.
But he who doubts is condemned if he eats, because he does not eat from faith; for whatever is not from faith is sin. Romans 14.23

The following comment then surges: Who will be saved by faith?

This question is answered when a person is baptized with the Spirit of Faith, the Holy Spirit.

Only those who are born of water and the Holy Spirit are able to live from faith to faith and by faith. This is because those born of the Spirit are spirit; this is, they are born of the Spirit of FAITH. Only those who are spirit (faith) have the necessary conditions to live in the Spirit (in faith).

To live by faith is to live in dependence of the Spirit of God. To live from faith to faith is to live in the Spirit and by the Spirit.

God is so merciful to us that before demanding us to live by FAITH, He gives us the Spirit of FAITH to make this possible. How could He charge us to live in faith and by faith if He doesn’t first give us the condition to do so?

When we promote the baptism with the Holy Spirit, it is precisely to obtain the power to live by faith and from faith to faith, knowing that you are unable to please Him and be saved when in doubt.

Faith is absolute certainty; there is no way to feel faith…

When there is absolute certainty, there is obedience to the One you have faith in.
This means: Faith + Obedience = Miracle