“Therefore, brothers, we have an obligation —but it is not to the sinful nature, to live according to it. For if you live according to the sinful nature, you will die; but if by the Spirit you put to death the misdeeds of the body, you will live,” (Rom 8:12, 13)
It couldn’t be clearer.
“This is the message we have heard from him and declare to you: God is light; in him there is no darkness at all. 6 If we claim to have fellowship with him and yet walk in the darkness, we lie and do not live out the truth.” (1 John 1:5, 6)
“No one who lives in him keeps on sinning. No one who continues to sin has either seen him or known him.
7 Dear children, do not let anyone lead you astray. The one who does what is right is righteous, just as he is righteous. 8 The one who does what is sinful is of the devil, because the devil has been sinning from the beginning. The reason the Son of God appeared was to destroy the devil’s work.” (1 John 3:6-8)
“Don’t you know that when you offer yourselves to someone as obedient slaves, you are slaves of the one you obey—whether you are slaves to sin, which leads to death, or to obedience, which leads to righteousness? 17 But thanks be to God that, though you used to be slaves to sin, you have come to obey from your heart the pattern of teaching that has now claimed your allegiance.” (Rom 6:16, 17)
“...thanks be to God that, though you used to be slaves to sin, you have come to obey from your heart the pattern of teaching that has now claimed your allegiance.”
According to Paul, if you are not trusting and obeying Jesus, you do not have faith in him.
Paul begins the book of Romans by saying he has been made an apostle to
“call people from among all the Gentiles to the obedience that comes from faith.” (Rom 1:5b)
We do, and if we are not confessing our sins and repenting of them, we will die in our sins (see 1 John 1:7-9). He purifies us from sin through repentance. (And slowly makes us like Christ. See here.)
“But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus, his Son, purifies us from all sin.” (1 John 1:7)
In all the epistles, the apostles are talking to two groups of people, those who are walking in the light, and those who are not. Over and over again they say those who walk in the light will inherit eternal life; and those who continue to sin will die. (The verses quoted above are but a small sample.)
If we are not obeying Jesus we should not assume that we have eternal life.
“But if this is true, How can anyone be sure of their final destination?”
Here is my answer to that question. Why Hell?