Another important passage which I should have mentioned is with that of Rom 8:26.
Rom 8:26 In the same way, the Spirit helps us in our weakness. We do not know what we ought to pray for, but the Spirit himself intercedes for us with groans that words cannot express. 27 And he who searches our hearts knows the mind of the Spirit, because the Spirit intercedes for the saints in accordance with Gods will.
Unlike Eph 6:18 and Jude 1:20 where the connection between praying in the Spirit and tongues is solid enough, particularly as Paul has already described praying with the S/spirit and praying with the mind in 1Co 14; this particular passage has been viewed in various ways over the years. Some have seen it as referring to how the Spirit allows us to pray perfect prayers or even that he intercedes on our behalf without us even being conscious of him doing so. Both of these views are certainly more than problematic which leaves us with us understanding that Paul is referring to how the Spirit prays through us in tongues.
David E Garland who wrote a 800 page book titled,
1 Corinthians, Baker Exegetical Commentary on the New Testament stated on page 585;
It is an expression of profound emotion from the deepest recesses of the soul that can be vocalised in prayer (14:2, 14, 28), singing, praise, and perhaps the sighs too deep for words (Rom 8:26).
Garland is certainly not a Pentecostal or Charismatic author and he mentioned that he comes to chapters 12, 13 & 14 at somewhat of a disadvantage as he is someone from the outside. He could possibly be referred to as being
open-but-cautious and it is interesting to read material by academics who are not Full Gospel who can effectively exegete passages that relate to the Holy Spirit.