When people hear the gospel the Holy Spirit works in them to persuade and convert them to a whole new life in Christ, but it's then good for them to voice what has happened, to speak to their Father in heaven. Evangelist Joseph Alleine (1634-1668) in his book "Alarm to the Unconverted" (now published as "A Sure Guide to Heaven") offers this 1000 word prayer that someone becoming a Christian could pray, or indeed any old Christian would benefit from...
'O most holy God, because of the cross of Your Son, accept Your poor prodigal now prostrating himself at Your door. I have fallen from You by my iniquity, and am by nature a son of death, and a thousand-fold more the child of hell by wicked practice. But of Your infinite grace You have promised mercy to me in Christ, if I will but turn to You with all my heart. Therefore, upon the call of Your gospel, I am now come in, and throwing down my weapons, submit myself to Your mercy. And because You require, as the condition of my peace with You, that I should put away my idols, and be at defiance with all Your enemies, which I acknowledge I have wickedly sided with against You, I here from the bottom of my heart renounce them all, firmly covenanting with You, not to allow myself in any known sin—but conscientiously to use all the means that I know You have prescribed for the death and utter destruction of all my corruptions.You'd be fairly well discipled, married to Christ the life-giving husband, by the time you finish praying that!
'And whereas formerly I have inordinately and idolatrously set my affections upon the world, I do here resign my heart to You who made it, humbly declaring before Your glorious Majesty, that it is the firm resolution of my heart, and that I do sincerely desire grace from You, that when You shall call me to, I may make it my resolution through Your assistance, to forsake all that is dear unto me in this world, rather than to turn from You to the ways of sin; and that I will watch against all its temptations, whether of prosperity or adversity, lest they should withdraw my heart from You. Help me against the temptations of Satan, to whose wicked suggestions I resolve by Your grace never to yield myself a servant. And because my own righteousness is but as filthy rags, I renounce all my confidence therein, and acknowledge that I am of myself a hopeless, helpless, undone creature, without righteousness or strength.
'And forasmuch as You have of Your bottomless mercy offered most graciously to me, a wretched sinner, to be again my God through Christ, if I would accept You; I call upon heaven and earth to record this day, that I do here solemnly avouch You for the Lord my God, and with all possible veneration, bowing the neck of my soul under the feet of Your most sacred Majesty, I do here take You the Lord Jehovah, Father, Son, and Holy Spirit, for my portion and chief good, and do give myself, body and soul, to be Your servant, promising and vowing to serve You in holiness and righteousness all the days of my life. 'And since You have appointed the Lord Jesus Christ the only means of coming unto You, I do here solemnly join myself in a marriage covenant to Him.
'O Blessed Jesus, I come to You hungry and thirsty, poor and wretched, miserable, blind and naked, a most loathsome polluted wretch, a guilty condemned criminal, unworthy to wash the feet of the servants of my Lord, much more to be solemnly married to the King of Glory. But such is Your unparalleled love, I do here with all my power accept You, and do take You for my Head and Husband, for better, for worse, for richer, for poorer, for all times and conditions, to love, honor and obey You before all others, and this to the death. I embrace You in all Your offices. I renounce my own worthiness, and do here avow You to be the Lord my Righteousness. I renounce my own wisdom, and do here take You for my only Guide. I renounce my own will, and take Your will for my law.
'And since You have told me that I must suffer if I will reign, I do here covenant with You to take my lot, as it falls, with You, and by Your grace assisting to run all hazards with You, truly supposing that neither life nor death shall part between You and me.
'And because You have been pleased to give me Your holy laws, as the rule of my life, and the way in which I should walk to Your kingdom, I do here willingly put my neck under Your yoke, and set my shoulder to Your burden; and subscribing to all Your laws as holy, just, and good, I solemnly take them as the rule of my words, thoughts, and actions; promising that though my flesh contradict and rebel—yet I will endeavor to order and govern my whole life to Your direction, and will not allow myself to neglect anything that I know to be my duty.
'Only because through the frailty of my flesh, I am subject to many failings, I am bold humbly to request, that unintentional shortcomings, contrary to the settled bent and resolution of my heart, shall not make void this covenant, for so You have said.
'Now, Almighty God, Searcher of hearts, You know that I make this covenant with You this day, without any known guile or reservation, beseeching You, that if You espy any flaw or falsehood therein, You would reveal it to me, and help me to do it aright.
'And now, O God the Father, whom I shall be bold from this day forward to look upon as my God and Father, glory be to You for finding out such a way for the recovery of undone sinners. Glory be to You, O God the Son, who have loved me and washed me from my sins in Your own blood, and are now become my Savior and Redeemer. Glory be to You, O God the Holy Spirit, who by the finger of Your almighty power, has turned about my heart from sin to God.
'O high and holy Jehovah, the Lord God Omnipotent, Father, Son, and Holy Spirit, You are now become my covenant Friend, and I through Your infinite grace am become Your covenant servant. Amen, so be it. And the covenant which I have made on earth, let it be ratified in heaven.'