Jesus taught them to pray with simplicity and humility.

⁷“And when you pray, do not heap up empty phrases as the Gentiles do, for they think that they will be heard for their many words. ⁸Do not be like them, for your Father knows what you need before you ask Him. ⁹Pray then like this: 

“Our Father in heaven, hallowed be Your name. ¹⁰Your kingdom come, Your will be done, on earth as it is in heaven. ¹¹Give us this day our daily bread, ¹²and forgive us our debts, as we also have forgiven our debtors. ¹³And lead us not into temptation, but deliver us from evil. (Matt. 6:7-13 ESV)

It’s important to note the following two verses:

¹⁴For if you forgive others their trespasses, your heavenly Father will also forgive you, ¹⁵but if you do not forgive others their trespasses, neither will your Father forgive your trespasses.