Ephesians 2:8–9 (ESV):

“For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast.”

Many interpreters (especially in Reformed theology) understand “this” (the Greek neuter touto) as encompassing the whole process of salvation by grace through faith, so that even the faith itself is part of God’s gift. Others argue the gift primarily refers to salvation as a whole, with faith as the means of receiving it. In either reading, the text stresses that nothing in the process originates from human merit or independent ability, which excludes boasting. 

(comment provided by Gotquestions)

A gift is useless if it is not opened and used.

James 2:26

For as the body apart from the spirit is dead, so also faith apart from works is dead.

Philippians 2:13

for it is God who works in you, both to will and to work for his good pleasure.

Galatians 3:5

Does he who supplies the Spirit to you and works miracles among you do so by works of the law, or by hearing with faith—

Faith is issued to us to accomplish the will of the Father which begins with hearing God.

Romans 10:17

So faith comes from hearing, and hearing through the word of Christ.

John 14:21

Whoever has my commandments and keeps them, he it is who loves me. And he who loves me will be loved by my Father, and I will love him and manifest myself to him.”

Using the faith that God gives us produces gratitude, joy, and love for the giver.

Romans 3:23-27 English Standard Version

 for all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus, whom God put forward as a propitiation by his blood, to be received by faith. This was to show God’s righteousness, because in his divine forbearance he had passed over former sins. It was to show his righteousness at the present time, so that he might be just and the justifier of the one who has faith in Jesus. Then what becomes of our boasting? It is excluded. By what kind of law? By a law of works? No, but by the law of faith.

Some say Jesus died just for their sins. Not true. Jesus put sin itself on trial and died to put an end to justification by obedience to the law. Sin is no longer the problem, it is not even considered.

Did you place your faith in His shed blood on the Cross?

If yes, you are justified by the blood.

If not, you are guilty of His blood.

That is a final court hearing and has nothing to do with the life you live now, by faith, or not.