Faith is only as good as its object. For instance, if I am planning to drive to Alaska and my tires are bald, absolutely no tread, but I say “I have faith they will get be there safely”; that is not faith, that is stupidity.
Saving faith is a trust, reliance, dependence upon the One who saves. It is not just a mental assent to some facts about Jesus. Many have this kind of faith, but it does not save because it is not a reliance upon another. Saving faith is in the person of Christ. He is indeed a personal Savior and we are to have a personal relationship with Him. Some seem to have a “head” knowledge of Jesus, but not a “heart” knowledge. They can quote Scripture, but their lives are out of harmony with Scripture. The faith that saves is the faith that obeys. I want to obey my Lord because I love Him. When it comes to His commandments, they are not grievous. Psalm 19 says they are sweeter than honey to the one who believes.
Eph. 2:8 says “For by grace are you saved through faith…” God offers salvation to all, but the gift must be accepted by faith. The one who is saved, is the one who in faith repents and is baptized. He is united with Christ when he is buried with Christ. After which he lives for Christ.