Colossians 4:2 (NKJV)
2 Continue earnestly in prayer, being vigilant in it with thanksgiving

 

1 Thessalonians 5:16-18 (NKJV)
16 Rejoice always,
17 pray without ceasing,
18 in everything give thanks; for this is the will of God in Christ Jesus for you.

 

Philippians 4:6 (NKJV)
6 Be anxious for nothing, but in everything by prayer and supplication, with thanksgiving, let your requests be made known to God;