Be perfect, as your Father in Heaven is perfect.
The Christian long game is essentially to work towards inner perfection, which then goes together with changes in behaviour. Eastern Orthodox traditions tend to get this right, with an emphasis on ‘theosis’, or becoming more like God.
How does one change one’s inner self? One important tool is through actions of thought. Collectively, these are called prayer in Christianity. It is important to note that ‘prayer’ is not a simple kind, but rather embodies different practices, many of which have as their goal the achievement of inner perfection.
This is to say, prayer is often not about changing the world ‘directly’, but changing oneself, which leads to things that change the world.
So, movement towards Inner pefection is typified by an increase in a kind of inner peace, a gradual change in one’s habitual thoughts, and these are then accompanied by changes in behaviour such as Jesus references before the quotation above.
So, certain kinds of prayer are different practices by which one can gradually refashion one’s habitual thoughts (and, therefore, actions or effects in the world).
As a rough categorization, these involve kinds of listening, meditation, visualization, contemplation, recitation that approximates what is known as ‘mantras’, and so on. This is complex, with some practices probably not achieving a significant result amongst some or most practitioners, while others have significant results.
So, within Christianity there are many practices. The question for an individual Christian is, which ones are the most relevant and effective for me at this point?