God answers the prayers of sinners, not perfect people.

In the version of the Lord’s Prayer in Luke 11:2–4, Jesus says, “When you pray, say . . . ” and then in verse 4 he includes this petition, “and forgive us our sins.” So, if you connect the beginning of the prayer with the middle, what he says is, “Whenever you pray, say . . . forgive us our sins.”
I take this to mean that this should be as much a part of all our praying as, “Hallowed be your name.” Which means that Jesus assumes that we need to seek forgiveness virtually every time we pray.

We are simultaneously sinners – doing evil in His sight – and redeemed. We are gradually overcoming our evil by the power of the Holy Spirit. But our native corruption is not obliterated by conversion.

We are sinners… and if we recognize this sin, renounce it, fight it, and cling to the cross of Christ as our hope, then God will hear us and answer our prayers.”
~ John Piper