If you feel you are ready to make a definite decision of your will to become a Christian, here are some practical steps to take:
If you feel you are ready now to truly repent and believe in Jesus, and you are genuinely serious about it, then go ahead and become a Christian now. There is no set formula for how you go about this, but, from experience, it may be helpful to do it broadly along the following lines:
Step one in becoming a Christian – repent towards God the Father
How to repent – what to do in practical terms
Get a pad of paper. Put the date at the top and write on it any specific sins, or transgressions or attitudes of rebellion that you feel aware of in your life. Write down anything that you are doing now or in the past that you can remember. Make the list as long as it needs to be. Ask God to help you remember the things He is most concerned about. He will bring to mind specific sins or transgressions, past or present, that He particularly wants you to repent of. They will be sins that are especially significant in your own life.
God will not bring everything to mind, because it would need a computer to deal with all your sins. What He will do is bring the most important or most relevant ones to mind. To start with it may only be a few. The exact number of sins you write down does not matter so much. What matters is that you seriously repent of them and really mean it.
You do not have to write things down if you prefer not to. You could just speak them out. But, writing does help to make it more real. Plus it is easier, later on, to look at it and feel sure that you really did this and that you meant it. I would advise it.
For each of the sins write down the name of the person who may have been affected by it. It could be your wife, children, employer, work colleague, friend or relative etc. Then alongside that name write down what you might be able to do to put it right. Sometimes it will not be possible to put it right. Sometimes it will. It may be that the most you can do is give an apology.
Other times you may be able to repay and put right the damage that you have caused in some practical way. For example, if you have been stealing from your employer or fiddling expenses, then you need to deal with that. It could be very hazardous to go to your employer and openly confess. That could result in dismissal or even prosecution. It is not always necessary to go that far. You need to be guided by your own conscience on that. There is a need to be practical and wise at the same time as being sincere.
If you have been stealing from your employer, then here is a good way to repay, without having to risk getting into serious trouble. You could set about working unpaid overtime for a sufficient period of time to more than pay back what you owe. Calculate on paper how much extra time you need to work secretly without claiming any pay for it.
Then quietly set about doing that extra work without telling anybody. In calculating it, err on the generous side. Make sure you fully repay or even over pay. This is practical repentance. It demonstrates to God that you mean what you say and you are not just being casual or shallow. There may be other ways that you can do it.
Apologies will be needed for many people, especially those closest to you such as your wife, children, parents or close friends. Where it is appropriate, go and see each person and apologise specifically for things that are suitable to raise. Do it unreservedly. Do not qualify your apology or seek to explain or justify your actions. Just straightforwardly apologise. Ideally, tell the person that you have become a Christian and feel you need to repent of what you did or said which has wronged them.
Be careful with this, however. Do not bring up painful things that are in the past and which would only cause even more pain and harm to others if they were to be openly raised again now.
Some things need to be repented of privately, just between you and God. You need to ask for the wisdom to know the difference. If however an apology will help and will not cause harm to that person or to anybody else, then go and directly apologise face to face with the person.
They may receive it well, or they may not. But whatever their reaction is, your going to them will please God, and it will help you to properly repent. However, do not go to people to tell them things you have said or thought about them which they are not aware of. That would only cause pain and upset them for no beneficial purpose.
Once you have written out your list of sins and areresolved to deal with them, don’t wait until you have spoken to the people on the list. You need to speak out your repentance towards God first. It’s important that you tell God out loud that you repent. Again, there is no formula for this, but it is a good idea to kneel down. You can do it on your own, or even better with a mature Christian to help you, and to be a witness to it.
If you are doing this with a genuine and mature believer alongside you, don't be ashamed to speak out loud and don't imagine that they will disapprove of you. They won't. They will just want to help you to get it all out and dealt with. They will have had similar sins in their own past.
Speak your repentance out loud to God the Father directly. Kneeling helps because it puts your body into a humble position. There is a direct relationship between the position of your body and the attitude of your mind. Altering your posture can really help to alter your attitude of mind.
You do not have to use eloquent words or indeed any particular form of words. Just speak in your own way with your own vocabulary. Tell God that you are sorry for the things that you have done and that you recognise that you have sinned against Him and others. Then apologise to Him directly. But only say it if you mean it. If you don’t yet mean it then persist with the preparatory steps I set out earlier, i.e. prayer and Bible reading, until you do really mean it.
Then ask God the Father for His forgiveness. Tell Him that you want to turn away from all your sins and that you want to renounce them and stop committing them. At the same time ask Him for His help in turning away from them, because on your own you cannot change or achieve anything.
Both you and God will know whether you are sincere in the prayer that you make. Therefore do not be phoney or try to kid God or yourself. Just be straight and come clean with God, without any pretentiousness.
Step two in becoming a Christian - believe in (or on) the Lord Jesus Christ
9That if you confess with your mouth, "Jesus is Lord," and believe in your heart that God raised him from the dead, you will be saved. 10For it is with your heart that you believe and are justified, and it is with your mouth that you confess and are saved. 11As the Scripture says, "Anyone who trusts in him will never be put to shame." 12 For there is no difference between Jew and Gentile—the same Lord is Lord of all and richly blesses all who call on him, 13for, "Everyone who calls on the name of the Lord will be saved." Romans 10:9-13 (NIV)
You need to be clear in your own mind that you believe the Bible and that you know and understand the main points that we need to believe in order to be a Christian. Please refer to the list of foundational things that you need to believe that was set out earlier in "Step 2 - believe" (chapter 15). I will reproduce the list here in short form, i.e. without the Bible verses in support.
Do remember, however, that believing in Jesus is not just a mental attitude that happens only in our minds. If it is real then it will show itself in what we do, i.e. in our actions and words. It will bring about a changed lifestyle.