Romans 5:1
Therefore being justified by faith, we have peace with God through our Lord Jesus Christ:
That passage does not say we are saved by faith. It says we are justified, saved, through or because of faith. Salvation is by grace alone, not faith. By the way that passage proves that faith is a work.
Eph 2:8,9
For by grace are ye saved through faith; and that not of yourselves: [it is] the gift of God:
Notice it is not by faith we are saved. It is not faith alone. It is grace alone when the person comes to repentance towards God ands faith in the Lord Jesus Christ. it is impossible to have faith without repentance.
If you don't understand the grammar of the verse I will explain it to you.
The verse is basically one simple subject and verb with a couple of definitive adverbial prepositional phrases.
The basic sentence is:
you are saved. Everything revolves around that sentence.
"By grace" is a prepositional phrase that defines the verb.
How is a person saved? He is saved by the grace provided by Christ on the cross. That is how. There is no other way to be saved but by the grace of God.
"through faith" is another prepositional phrase that defines the verb.
By what means is a person saved. A person is saved through faith. There is no other means by which a person can be saved but by putting faith in the one that saves. Unless he accepts the sacrifice of Christ by faith and faith alone he cannot be saved.
"and that not of yourselves." To emphasize the point of faith, Paul adds this phrase that there is no merit of oneself, no work that can be done of oneself that can merit salvation. Salvation is not of oneself. It is of God, and through faith in God's provision.
It is the "gift of God." Salvation is the gift of God. Being a gift it must be accepted by faith. There is no other way to accept a gift except by faith. Salvation is God's gift to man. Accept it by faith.
It is not of works. Again Paul emphasizes that there are not works involved in salvation. Salvation is not of works. It is of faith. It must be accepted by faith and faith alone. That sacrifice of the grace of God can only be appropriated by faith. Thus salvation is by faith.