First, do you believe that you can die in unrepentant sin (such as lying and or lusting after a woman) and still be saved? Yes or no?
Second,
2 Timothy 2:13 is not a license for you to sin on occasion or for you to mimimize the punishment of sin leading to spiritual death for the believer. This verse says God is merely faithful if we believe not. Verse 13 (by itself) does not say WHO or WHAT God is faithful to. However, it gives us a clue as to what or who God is faithful to because it says He cannot deny Himself. God's Word is the part of God that He cannot deny. God remains faithful to His Word even if you do not believe.
John 3:18 says he that does not believe is condemned. Again,
2 Timothy 2:12 gives us the context of
2 Timothy 2:12. If you deny Him, he will deny you.
God is faithful to His Word.
"So God has given both his promise and his oath. These two things are unchangeable because it is impossible for God to lie. Therefore, we who have fled to him for refuge can have great confidence as we hold to the hope that lies before us." (
Hebrews 6:18 NLT).
Notice again here the verse does not say God is faithful to you if you believe not. The Scriptures say that, "without faith, it is impossible to please Him" [God] (
Hebrews 11:6).
"Behold therefore the goodness and severity of God: on them which fell, severity; but toward thee, goodness, if thou continue in
his goodness: otherwise thou also shalt be cut off." (
Romans 11:22).
"For if God spared not the natural branches,
take heed lest he also spare not thee." (
Romans 11:21).
19 "...The branches were broken off, that I might be graffed in.
20 Well; because of
unbelief they were broken off, and
thou standest by faith. Be not highminded, but fear" (
Romans 11:19-20).
"
Take heed, brethren, lest
there be in any of you an evil heart of unbelief, in departing from the living God" (
Hebrews 3:12).
"But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin." (
Hebrews 3:13).
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