1 Thessalonians 5: 16-28 begins with the instruction to rejoice, pray and more.
16 Rejoice evermore. 17 Pray without ceasing. 18 In every thing give thanks : for this is the will of God in Christ Jesus concerning you. 19 Quench not the Spirit. 20 Despise not prophesyings. 21 Prove all things; hold fast that which is good. 22 Abstain from all appearance of evil. 23 And the very God of peace sanctify you wholly; and I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ. 24 Faithful is he that calleth you, who also will do it. 25 Brethren, pray for us. 26 Greet all the brethren with an holy kiss. 27 I charge you by the Lord that this epistle be read unto all the holy brethren. 28 The grace of our Lord Jesus Christ be with you. Amen.
In the book of Romans Paul wrote:
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. (Romans 8:26)