To Becoming Acceptable to God

Q. Why do I say that I am righteous only by faith? 

Not that I am acceptable to God on account of the worthiness of my faith, for only the satisfaction, righteousness and holiness of Christ is my righteousness before God. 

1 Corinthians 1:30,31 But of Him you are in Christ Jesus, who became for us wisdom from God; and righteousness and sanctification and redemption; that, as it is written, “He who glories, let him glory in the LORD.” 

1 Corinthians 2:2 For I determined not to know anything among you except Jesus Christ and Him crucified.

I can receive this righteousness and make it my own by faith only.

Romans 10:10 For with the heart one believes unto righteousness, and with the mouth confession is made unto salvation. 

1 John 5:10-12 He who believes in the Son of God has the witness in himself; he who does not believe God has made Him a liar, because he has not believed the testimony that God has given of His Son.  And this is the testimony: that God has given us eternal life, and this life is in His Son. He who has the Son has life; he who does not have the Son of God does not have life.

The Heidelberg Catechism Lord's Day 23