Encouraged to pray by a sure hope

Calvin's Institutes (1559)
Book 3 of 4 - How We Receive the Grace of Christ

Chapter 20 - Prayer as exercise of faith and way we receive God's benefits

Sections 4-16 - Rules of prayer

Sections 11-14 - 4th rule: Pray with confident hope

11. While humbling ourselves before God in fear, we are also to take encouraging refuge in Him, trusting He will hear us. Faith is our guide in prayer, and obtains what is sought - Mark 11:24; Matt 21:22; James 1:5-7; Rom 10:14, 17.

12. We don't come uncertain if God will hear us, as if that were a mark of piety - Heb 4:16; Eph 3:12; Ps 33:22; 56:9; 5:3. We do come with anxiety over our sin and trials, but we unburden ourselves before Him "as children unburden their troubles to their parents." See Ps 41:4.

13. We can pray like this because God commands us to, and promises to answer - Ps 50:15; Matt 7:7; Ps 65:1-2; 145:19.

14. We should pray "without terror but with reverential fear." We should also be confident, for He promises to hear us - Jer 2:13; Prov 18:10; Joel 2:32; Rom 10:13; Acts 2:21; Isa 65:24; Ps 91:15; 145:18; 1 Pet 5:7; 2 Sam 7:27-29; Ps 119:76; Gen 32:10-13.