There are three devastating results of ongoing sin for a Christian: A hindered relationship with God, slavery to sin, and the loss of eternal rewards.
1. A hindered relationship with God. Actually, when a Christin sins there is an immediate spiritual death, because Romans 6: 23 says, “For the wages of sin is death.” This death will not affect your eternity with God if you are a Christian; however, sin always puts a wall between us and God, because the holiness of God cannot have fellowship with one who dwells in sin. Thus, as long as your sin is unconfessed it hinders (blocks off until confession and repentance is made) the relationship you have with God. This is why it is so important to confess our sins as soon as possible after we sin.
2. Slavery to sin. Many that have played around with sin too long (even fantasizing about it), have found it difficult to repent—and the results have been devastating! The longer we sin without repenting of it, the tighter the grip sin will have on us, and soon we will be its slave. Here is an excellent passage on this:
Romans 6:12, 16
Therefore do not let sin reign in your mortal body that you should obey its lusts…
16 Do you not know that when you present yourselves to someone as slaves for obedience, you are slaves of the one whom you obey, either of sin resulting in death, or of obedience resulting in righteousness?
3. Loss of eternal rewards. As soon as Christ comes to take us to heaven we will first appear before the judgment seat of Christ (2 Cor. 5:10)—where He will reward us for our works…or not. We will not be judged for our sin. That has been taken care of at the cross. But ongoing sin will affect how we live for Him—what we do for Him. And if sin has prevented you from doing good works, this will have devastating eternal consequences. Don’t let ongoing sin ruin your eternity!