St Alphonsus teaches that the prayer of petition is simply and absolutely necessary for salvation for those who have the use of reason -- if we want to go to heaven, we must ask; and if we don't ask, we certainly will not be saved.
This follows from our Lord's words: Ask and you will receive, seek and you will find, knock and the door will be opened to you.
But, in order that we may persevere in asking, it is also necessary that we daily engage in mental prayer or meditation in which we spend time considering the love of God that has been made manifest in Christ.
This is one of the keys to prayer, and especially to dealing with the struggle of distractions: We don't begin our prayer with all our petitions or all our cares, but rather we begin by meditating upon the mysteries of our faith (for example, the mysteries of the Rosary or the stations of the Cross) and upon the love God has shown us in these mysteries. Then we have the courage to ask God for every good gift, and our own love grows and inspires us to truly seek heaven above all things.
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