Salvation is a gift that we receive by having faith in God. Because of God's merciful and loving-kindness he graciously set us free from sin. God made Jesus who knew no sin to be sin for us so that we might be made the righteousness of God. Jesus fulfilled the law so that we may live under the period of grace and have everlasting life. The only thing necessary for us to do to attain salvation is for us to believe in our heart and confess with our mouth the Lord Jesus and that God raised him from the dead.
For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him. 2 Corinthians 5:21 (KJV)
But what saith it? The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach; That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believes unto righteousness; and with the mouth confession is made unto salvation. For the scripture saith, Whosoever believeth on him shall not be ashamed. For there is no difference between the Jew and the Greek: for the same Lord over all is rich unto all that call upon him. For whosoever shall call upon the name of the Lord shall be saved. Romans 10:8-13
But without faith it is impossible to please him; for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him. Hebrews 11:6