In John 3:16 the Bible says, "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life." The word believe in this verse means to continually trust in, commit to and rely on Jesus, day after day. It is far more than a once off 'thank you Jesus.' Anyone who fails to rely on Jesus daily will soon fall into sin. 1 John 3:6 says, "No one who lives in him [Jesus] keeps on sinning. No one who continues to sin has either seen him or known him." and 1 John 3:9 says, "No one who is born of God will continue to sin..." From these verses it is quite clear that if someone is continuing in deliberate sin then he does not know Jesus and is not born again ... Jesus said you must repent and be born again to inherit the kingdom of God (Luke 13:3 & John 3:3).
Many people believe that Jesus died for all their sins, both past and future. They say that once a person is saved even if they fall into deliberate sin then they have not lost their salvation but have just lost fellowship with Jesus. They say that they are 'washed in the blood' and are saved no matter what they do because Jesus shed his blood for all their sins, past, present and future. These misguided souls fail to understand that without repentance there is no salvation (Luke 13:3). Repentance is turning away from a life of sin and becoming a new creation (2 Cor 5:17). There is not a single verse in the Bible which says our future sins are forgiven but there are many to say that if we continue in deliberate sin, we will be lost. Please read Col 3:5-10 & Psa 19:13). The article Perseverance Of The Saints gives many verses pointing to the possible loss of salvation if someone continues in deliberate sin.
It makes a mockery of Jesus' death to believe that we can say to Him, "Thanks for dying for my sins Jesus, now I'm going to jump in bed here, get drunk, tell a few lies etc." The Bible says in 2 Cor 5:17, "...if anyone is in Christ, he is a new creation; the old has gone, the new has come." If any person, a professing Christian or otherwise, does not turn from their sinful ways but remains in sin then they face hell as "the wages of sin is death" (Romans 6:23). Jesus came to "save his people from their sins" (Matt 1:21), not to give them a license to sin.
Please read Are You Saved to understand the vital need we have to walk in the Spirit daily, in order to be kept from sin. The Holy Spirit is sent into the lives of believers to give them the power needed to defeat their sinful nature and live a holy life, pleasing to the Lord. Hebrews 12:14 says that "without holiness no one will see the Lord." The Power Of Sin is a personal testimony of sin's enormous and ongoing power over us and the need we have for constant reliance on the Holy Spirit to keep us from falling.
Click here for my YouTube videos on salvation, including one called Grieving The Spirit.