But as many as received him [Jesus Christ], to them gave he power [the right] to become the sons of God, even to them that believe on his name. — JOHN 1:12

Receiving Jesus Christ is an act of the will. So man acts on the Word of God by an act of his will. Man knows he is without a Savior, without an approach to God, without eternal life, so he can look up to God and pray, in essence:

Father, I come to You in the Name of the Lord Jesus Christ. I know You will not turn me away, or cast me out, because You said in Your Word, “. . . him that cometh to me I will in no wise cast out.” I believe in my heart that Jesus Christ is the Son of God. I believe that He died for my sins, according to the Scriptures. I believe that He was raised from the dead for my justification, according to the Scriptures. “Justification” means that I might be set right with God. I believe that because of His death, burial, and resurrection, I am set right with God. So I receive Jesus as my Savior, and I confess Him as my Lord. Your Word says, “Whosoever shall call upon the name of the Lord shall be saved.” I am calling on You now, so I know I am saved. And You said, “If thou shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.” I’m confessing that with my mouth. I believe it in my heart. So I am saved. You said, “. . . with the heart man believeth unto righteousness.” And with my heart I believe that I am made right with God. And You said, “. . . with the mouth confession is made unto salvation.” So with my mouth I confess, I am saved! Thank You, Lord!