The only troubling verses I find are these...
1 Thess 4:3-8
For this is the will of God, your sanctification: that you should abstain from sexual immorality; 4 that each of you should know how to possess his own vessel in sanctification and honor, 5 not in passion of lust, like the Gentiles who do not know God; 6 that no one should take advantage of and defraud his brother in this matter, because the Lord is the avenger of all such, as we also forewarned you and testified. 7 For God did not call us to uncleanness, but in holiness. 8 Therefore he who rejects this does not reject man, but God, who has also given us His Holy Spirit.
NKJV
"The Lord is the "avenger" of such, is what we are not told in detail of what may transpire.
No, I did not believe Jesus was literally saying cut off a hand or foot, but was making a strong point concerning sin.
This verse tell the young Christians in Thessalonika what the will of God is. It also reminds them that they were forewarned. And testimony was given to them concerning the matter.
You are right that the avenging by God is not specifically detailed here. The culture and atmosphere of immorality was probably so strong in that ancient city that Paul had to speak like this.
Our escape is only in the indwelling Spirit of Christ who is in our spirit. We have to turn to that realm and abide in our regenerated spirit where Christ the Overcomer is.
John says that
"everything" that has been begotten of God overcomes the world -
" For everything that has been begotten of God overcomes the world, and this is the victory that overcomes the world - our faith. And who is the one who overcomes the world except hom who believes that Jesus is the Son of God." (1 John 5:4,5)
If we are Christians our innermost part of our being, our human spirit has been begotten of God. The regenerated spirit that is united with the Holy Spirit is the part of us which overcomes the world. So we must turn to our spirit where we touch Christ.
"He who is joined to the Lord is one spirit" (1 Cor. 6:17) shows that our human spirit has been joined to the Lord Jesus so that Christ and our innermost spiritual being are united. No wonder this
"everything" which has been begotten of God and
"joined to the Lord" overcomes the world.
So we must not fall into the trap of gritting our teeth and trying to resist temptations in our natural religious or ethical zeal. That will not work and will likely backfire. But we have to have faith that the Son of God is joined to our innermost spirit - Jesus Christ is in us. And we call on Him -
"O Lord Jesus. You are the Son of God and You live in Me. O Lord Jesus You handle this Lord. O Lord Jesus, I turn to my spirit where You are Lord. Praise the Lord, Lord You overcome the world."
This is an enjoyment to contact Christ in this way. The greater enjoyment will swallow up the lesser enjoyment - that enjoyment of sinning which only results in death and self condemnation afterwards.
This is why I said we have to enjoy something else. We have to enjoy calling on the Lord Jesus bring our mind into His presence. Actually we should learn to linger in this realm and walk in this realm. If we only wait to be in trouble to turn to the Lord Jesus it will not work too well. But if we log more time in the Spirit as we abide in Him, we will be overcoming in Him.
Notice also Paul talked about those who do not know God. John says a similar thing. That is that if we practice sinning we have not seen God and do not know God. It is subjective and experiencial.
"Everyone who abides in Him does not sin; everyone who sins has not seen Him or known Him." (1 John 3:6)
This is not too doctrinal but experience related. We have to pray
"Lord Jesus I turn to my spirit that I may see You. Lord Jesus I turn to the Lord that I may know you."
This is also not a purely individualistic matter. But if we turn for the sake of not only ourselves but for the other members of Christ's body which we know and love we express our love for them by our abiding in Christ and overcoming. Notice the context:
"In this we know that we love the children of God, when we love God and keep His commandments,
For this is the love of God, that we keep His commandments; and His commandments are not burdensome.
For everything that has been begotten of God overcomes the world ..."
His commandments are not burdensome because the Holy Spirit in our spirit is like the power steering of an automobile. Just a little cooperation and His grace flows through us.
And sometimes if I have just the thought of the faces of some other Christians with whom I am closely associated with before me, I know that my overcoming is also beneficial to them. Thus the love of the brotherhood is expressed in my turning to my overcoming spirit. And love horizontal is power as love vertical is power.