Let's look at Hebrews 12, which explains where faith comes from.
Hebrews 12:1-2
Therefore, since we are surrounded by so great a cloud of witnesses, let us also lay aside every weight, and sin which clings so closely, and let us run with endurance the race that is set before us, looking to Jesus, the founder and perfecter of our faith, who for the joy that was set before him endured the cross, despising the shame, and is seated at the right hand of the throne of God.
The question is this:
Did Jesus author (found) faith for all humans at their conception, yet only perfect the faith of some...or did Jesus author faith at the moment he graciously saved a person so that they would believe, which then carries over to perfecting this faith in the believer?
Notice Peter tells us that the cause of our faith is Jesus.
1 Peter 1:3-5,8-9,20-21
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, to an inheritance that is imperishable, undefiled, and unfading, kept in heaven for you, who by God’s power are being guarded through faith for a salvation ready to be revealed in the last time.
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, obtaining the outcome of your faith, the salvation of your souls.
He was foreknown before the foundation of the world but was made manifest in the last times for the sake of you who through him are believers in God, who raised him from the dead and gave him glory, so that your faith and hope are in God.