I'm not talking about faith in something - it's faith in Someone - Jesus Christ. Saving faith in Christ is justification and eternal life. This saving faith should produce results which are expanded on in the Epistles. Nothing Jesus says indicates that we have to do something to keep our salvation.
James 2:14-26, "14 What use is it, my brethren, if someone says he has faith but he has no works? Can that faith save him? 15 If a brother or sister is without clothing and in need of daily food, 16 and one of you says to them, "Go in peace, be warmed and be filled," and yet you do not give them what is necessary for their body, what use is that? 17 Even so faith, if it has no works, is dead, [being] by itself. 18 But someone may well say, "You have faith and I have works; show me your faith without the works, and I will show you my faith by my works." 19 You believe that God is one. You do well; the demons also believe, and shudder. 20 But are you willing to recognize, you foolish fellow, that faith without works is useless? 21 Was not Abraham our father justified by works when he offered up Isaac his son on the altar? 22 You see that faith was working with his works, and as a result of the works, faith was perfected; 23 and the Scripture was fulfilled which says, "And Abraham believed God, and it was reckoned to him as righteousness," and he was called the friend of God. 24 You see that a man is justified by works and not by faith alone. 25 In the same way, was not Rahab the harlot also justified by works when she received the messengers and sent them out by another way? 26 For just as the body without the spirit is dead, so also faith without works is dead."
A genuine saving faith is accompanied by works. A genuine saving faith in Jesus Christ is proven by the works that accompany it. One who believed in Jesus Christ at that time was baptized. By naming Christ as Lord meant that the emperor could have had that person executed.
An alive faith in Jesus Christ shows.
A creedal faith is nothing more than intellectual faith disguised as genuine faith. I have never seen a person who is genuinely saved and obedient who has not made disciples.