Faith in the Son -> eternal life with the Father -> answered prayer
Our newly found eternal life in the Son of God is confirmed by answered prayers. God is no longer our judge temporarily withholding eternal judgment, but has become our Father extending blessings that include answered prayer (Jn.15:7).
What would Jesus pray for
Our prayers are properly lined up when they are directed to the Father in the name of Jesus---meaning the content is to be consistent with what we know Jesus would want. Our prayers are then lined up with God's will and positioned to be answered with joy (Jn.16:23-24, Ja.4:3).
A prayer that pleases
For example, if our prayers are about bearing fruit for Jesus we can be sure that they will be answered (Jn.15:16).
Pure and earnest
Confession is key to maintaining prayers that are pleasing to God and open to answers (Ps.66:18, Ja.5:16). When we sin, we fall away from Jesus (Pro.20:8-9), but when we confess our sins we fall onto his righteousness and are washed and
have restored fellowship (1Jn.1:9).
Delight in the Lord, and he will give you the desires of your heart (Ps. 37:4)