The Cross and The Shedding of Blood

Because Jesus died upon the cross our sins may be forgiven, if we accept the payment and act upon it. We sometimes think that just because we mouth a few words in the "sinner's prayer", we have said the magic words for salvation. Unfortunately, this is not necessarily the case, these words must come from a broken and contrite heart, the Holy Spirit must bring the conviction in your heart to be able to accept salvation or else you are still blinded by your old sin nature and cannot see that you are spiritually dead and in need of Christ's atonement. The job of any Christian should be to share about what Christ has done for us and boldly share the gospel message, the Holy Spirit will use our efforts and convict the sinner of their reality, once realized, we may lead a person in prayer, but the heart change occurs from within not without, the words must spring forth from the broken heart, not just as joining a club or fraternity, but as being pulled from drowning in a river or burning in a hellish fire. The Cross is central to the Christian life always has been and always will be. We first read in Leviticus the prescription for the sacrifices to cover various sins of mankind, the Jewish Nation was being shown the necessity of the shedding of blood to cover sins and allow for fellowship with Yahweh God, indeed the first shedding of blood was performed by Yahweh himself in the garden when skins were used for clothing to cover Adam and Eve, what a horror that was for them to behold, an indelible picture of the true horrendous nature of sin and it's consequences.
So it was that Jesus came to pay the ultimate sacrifice in due time, the perfect life that could only be lived by a man being born not into sin, but into the world, born fully God and fully man. What love our Father has for us, to send His only begotten Son into the jaws of sin to pay for our debts, so we may not be lost, but saved from eternal death. The power in the cross is that it was the ultimate act of obedience by Jesus unto horrendous torture, done out of unfathomable love for you and me. The death(sacrifice) paid the price, once and for all, the resurrection validated the work, it was a total package for redemption, there was no payment for us if there was no resurrection, yet there was no resurrection without a sinless life, what glorious tapestry of love our Father has woven for us.
How is it we say, we may live according to our own ways and desires? Are we not bought with a price? Don't we owe our very life to the One who saved us? Holiness and Purity must be the lifestyle we seek, changed precept by precept, line upon line, action by action. It must be the desire of our heart. It may take time to take root in our heart, but we must never quit moving toward the goal of a righteousness in our behaviors and actions, to live up to the work that has been performed in our hearts.
Behavioral changes sometimes take time, but there must be a change reflected in the man or woman after salvation, a light that reflects something of the Lord, a difference or witness to the change of heart. If you are uncertain in your heart, be certain! Accept Christ's payment and live for Him today.
Romans 10:

9 that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved. 10 For with the heart one believes unto righteousness, and with the mouth confession is made unto salvation. 11 For the Scripture says, “Whoever believes on Him will not be put to shame.” 12 For there is no distinction between Jew and Greek, for the same Lord over all is rich to all who call upon Him. 13 For “whoever calls on the name of the LORD shall be saved.” 

The link below provides good scriptural references about the cross:

 http://www.crossroad.to/HisWord/verses/topics/cross.htm