I know two things.
#1. One must obey the gospel to be saved (Ac.2:40) (2Thess.1:7-9) (Mark 16:15,16)(Mt.7:21).
#2. Those saved can so sin to be lost b/c of what I read in (1Jn 1:6-9).
6 If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth: 7 But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin.
8 If we say that we have no sin, we deceive ourselves, and the truth is not in us.
9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
"We" refers to the saved (vs6)
"walk in darkness" refers to a sinful lifestyle (vs 6)
"Do not the truth" refers to sinful lifestyle (rejecting truth) (vs 6) (Jn 12:48).
But "If" (upon the condition that) we walk in the light (do right) we have a relationship with Christ and our brethren and our sins are cleansed.
Notice our relationship with Christ is conditional based upon our lifestyle.
Doctrine and the correct doctrine is important according to (vs 8) (1Cor.1:10) (1Tim.4:1-3)(2Tim.4:1-4) (1Tim.1:3).
"If" (upon the condition that) one saved will "confess" his sins he can be forgiven and will not be lost (vs 9)
One must "do truth" to be saved (Jn 3:19-21) (Mt.7:21) (1Jn 2:3,4).
21 But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God. (Jn 3:19)
3 And hereby we do know that we know him, if we keep his commandments. 4 He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him. 5 But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him. 6 He that saith he abideth in him ought himself also so to walk, even as he walked. (1Jn 2:3,4)
we know him, if we keep his commandments
He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him.
the truth is not in him.
whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him.
How do we know we are saved? (1Jn 2:3,-6)
If we do truth (obey the gospel). (Jn 3:19-21)
Believe + Baptism = Saved (Mk 16:15,16)
Thanks