Romans

"In the same way the Spirit also helps our weakness; for we do not know how to pray as we should, but the Spirit Himself intercedes for us with groanings too deep for words" (Romans 8:26 NASB1995).

When a person has no words, or is unable to word what is to deep for words, the Spirit speaks for us. He reads our heart, and he understands our sorrows (Romans 8:27). "When the Christian’s prayers are too deep and too intense for words, when they are rather a sigh heaved from the heart than any formal utterance, then we may know that they are prompted by the Spirit Himself. It is He who is praying to God for us" (Ellicott).

"[W]ith inward sighs and groans, which cannot be expressed by words. There may be prayer, where there is no speech or vocal expression. A man may cry, and that mightily to God, when he uttereth never a word" (Poole).

Dearly beloved, avenge not yourselves, but rather give place unto wrath: for it is written(see Deuteronomy 32:35), Vengeance is mine; I will repay, saith the Lord.

Paul is saying a person should not take revenge, but instead, allow God to judge them. All sins must be paid, if you are in the old covenant(which you are not) God tells one to do sacrifice(read Leviticus for more). If you are in the new covenant, Jesus' payment on the cross can subdue God's vengeance. If one does not accept Jesus, then the person must pay for their crime in Sheol. An unfun place indeed.