"And pray in the Spirit on all occasions with all kinds of prayers and requests.  With this in mind, be alert and always keep praying for all the saints." 
Ephesians 6:18

"The Lord detests the sacrifice of the wicked, but the prayer of the upright pleases Him." 
Proverbs 15:13

"Be joyful always; pray continually; give thanks in all circumstances, for this is God's will for you in Christ Jesus." 
I Thessalonians 5:16