Is the Pentecostal concept of "praying in the Spirit" consistent with any pre-Pentecostal teachings?

I agree with Bye's answer that praying in the Spirit can mean what is spoken of in Romans 8:26-27 about the Spirit offering up groanings on our behalf when we can't find the words. But there is another passage I think needs to be mentioned as well. Paul himself dealt with those who interpreted praying in the Spirit as meaning speaking in tongues, and he absolutely disagreed with them.

1st Corinthians 14:13-20

13 Wherefore let him that speaketh in an unknown tongue pray that he may interpret.

14 For if I pray in an unknown tongue, my spirit prayeth, but my understanding is unfruitful.

15 What is it then? I will pray with the spirit, and I will pray with the understanding also: I will sing with the spirit, and I will sing with the understanding also.

16 Else when thou shalt bless with the spirit, how shall he that occupieth the room of the unlearned say Amen at thy giving of thanks, seeing he understandeth not what thou sayest?

17 For thou verily givest thanks well, but the other is not edified.

18 I thank my God, I speak with tongues more than ye all:

19 Yet in the church I had rather speak five words with my understanding, that by my voice I might teach others also, than ten thousand words in an unknown tongue.

20 Brethren, be not children in understanding: howbeit in malice be ye children, but in understanding be men.

Praying in an unknown tongue is not praying in the Spirit, and praying in an unknown tongue in public worship doesn't edify anyone, since they don't understand what was said and therefore cannot say "Amen" to the prayer, so Paul says stick with a language everyone can understand in public prayer.

Edit:-- I will add the "the spirit" here seems not to even be the Holy Spirit but the human spirit. The idea behind praying in or with the spirit seems to be to pray with sincerity, i.e. from the heart. Even when it comes to tongues, Paul here attributes it to the human spirit, in verse 14, "For if I pray in an unknown tongue, my spirit prayeth, but my understanding is unfruitful." The important thing in praying "in the spirit" is praying sincerely, from the heart. But when people pray in an unknown tongue, their heart may be in it apart from the intellect, which is what Paul is saying should not be done.

What do you mean by "Pre-Pentecostal" teachings? (What we call) the Pentecostal church was born on the day of Pentecost. It was not called the Pentecostal then, but before there was the "Pentecostal-by-name" church, there was the Baptist church who believed just as we do today. There are records of Baptist being baptized in Jesus name and them having loud services. "Pentecostal" only came into use after about 1900-1950, but the doctrine of the apostles (long hair and dresses on women, short hair on men, tongue-talking, shouting, etc.) was born long before then. That is where "Apostolic" or "Apostolic Pentecostal" comes from, the doctrine of the Apostles (Apostolic) and the Day of Pentecost experience (speaking in tongues, etc.).

Well, praying in the Spirit is speaking in tongues. Now, Paul did write against certain times speaking in tongues, but one must think of the people he w as writing to. The church he wrote that to had to learn to let the spiritual gifts (like tongues) go in a way that did not cause confusion. The church he wrote to was not doing anything wrong in using the gift of tongues, but that they did it in a way that it was confusing. Paul said "I speak in tongues more than you all", he said that to prophesy is better than tongues, in that it edifies the whole church and builds it up. He also said speaking in tongues edifies the one doing it. Certain tongues are to he interpreted, while others are just that, unknown. Speaking in tongus is a gift and is meant to be used, it strengthens the tongue-talker, and is a sign to unbelievers.

Pentecostalism, especially given their description in the Azusa Street form, and which is generally recognised as the beginning of this revivalism movement, at least to me, appears quite close to Quakerism:

also known as the Religious Society of Friends ... and are united by their belief in the ability of each human being to experientially access the light within, or that of 'God within.'

Pentecostalism, taking its cue from Acts, in this sense very close to Quakerism.

Unfortunately, in my opinion, no at least for Eph 6:18 and Jude 20-21.

It is a strange new world to know that the Bible is not merely a historical document to be studied and analyzed, it is a life-giving and nourishing word that we should long for, taste, and eat.

…Long for the guileless milk of the word… –1 Pet. 2:2

How sweet are Your words to my taste! –Psa. 119:103

Your words were found and I ate them… –Jer. 15:16

Beginning from Origen, the early Christians referred to this as lectio divina (divine reading). Also from every period of church history, including Origen, Jerome, Ambrose, Augustine, Gregory the Great, Martin Luther, John Calvin, John Wesley, Andrew Murray, W. H. Griffith Thomas etc.

Although definitions abound, Mariano Magrassi in his book, Praying the Bible, summed it in this quote:

We find that Leclercq’s definition, brief and concise as it is, gets to the heart of the matter: ‘Lectio divina is prayed reading

and

In order to pray, we do not need to rack our brains, artificially evoking interior acts, thoughts or excessively refined affections. All we need to do is react in the presence of the text with free and spontaneous prayer. And when this spontaneous outpouring stops, we return to the text for fresh nourishment.

E. M. Bounds in the his book, The Necessity of Prayer, says:

The Word of God is made effectual and operative, by the process and practice of prayer… the Word of God is the food, by which prayer is nourished and made strong.

Lastly, we should also put verse 17 of Ephesians 6 with verse 18:

17 And take the helmet of salvation, and the sword of the Spirit, which is the word of God.

18 With all prayer and petition pray at all times in the Spirit, and with this in view, be on the alert with all perseverance and petition for all the saints,

Paul is actually telling us to pray-read or pray with the Word.

Thomas Aquinas on 1 Cor. 14

What am I to do? Because someone could say: inasmuch as prayer in a tongue is without fruit to the mind, but the spirit prays, should one then not pray in the spirit. Therefore, the Apostle answer this objection, saying that one should pray in both ways, in the spirit and in the mind; because man should serve God with all the things he has from God. But from God he has spirit and mind; therefore, he should pray with both: “With all his heart he will praise God” (Sir 47:8). Therefore, he says: I will pray with the spirit and I will pray with the mind also; I will sing with the spirit and I will sing with the mind also. And so he says that he will pray and sing; because prayer is the beseeching of God, and so he says, I will pray, or it is praising Him, and so he says I will sing. Concerning these two Jas (6:13) says: “Is anyone among you suffering? Let him pray. Is any cheerful? Let him sing.” “Sing praises to the Lord” (Ps 9:11). I will pray, therefore, in the spirit, i.e., imagination, and with the mind, i.e., the will.

Origen in his example of the inner working of the Triune God in prayers from 1 Cor 14:15 commented:

I will pray in the Spirit, and I will pray in the mind also ... For our mind cannot pray unless the Spirit prays first ... just as it cannot sing out .... hymning the Father in Christ, unless the Spirit which searches all things, even the depths of God, first gives praise and hymns him who depths he has searched out and, as he is able, comprehended.

Origin identifies as necessary in writing about prayer is, "The illumination of the Father is needed", "as well as the teaching of the firstborn Word and the inner working of the Spirit".

Carol Harrison says that according to Origen, "... God's Trinitarian work as Creator, Redemer and illumniator/inspirer therefore provides the grounds for prayer;"

Praying in the Spirit is a concept that was put forth by Paul in the book of Romans.

Romans 8:26 and 27 Likewise the Spirit also helpeth our infirmities: for we know not what we should pray for as we ought: but the Spirit itself maketh intercession for us with groanings which cannot be uttered. 27 And he that searcheth the hearts knoweth what is the mind of the Spirit, because he maketh intercession for the saints according to the will of God.

The underlying thought appears to be that since God is Spirit that communication between our spirit and Spirit God so to speak have their own language as indicated by intercession for us with groanings which cannot be uttered.

And in verse 27 he that searcheth the hearts knoweth what is the mind of the Spirit, appears that the Spirit itself has a mental process foreign to ours, and that God looks at our hearts rather than our entreaties.

Hope this helps.

As a student of Pentecostal history and a practicing charismatic/Pentecostal, the simple answer to your question is no, it is not the meaning all church history pre dating Pentecostalism put on those scriptures.

There is a huge period of cessationism in the church

For a full research on tongues through out history go here

http://www.brothermel.org/sites/default/files/articles/MCM_Tongues_in_Early_Church_History_Final_0.pdf