I commend your desire to lead your boy to Christ and my answer is not intended to put down your intention, but hopefully to redirect it.
Altar call - From Wikipedia:
An altar call is a practice in some evangelical churches in which those who wish to make a new spiritual commitment to Jesus Christ are invited to come forward publicly. It is so named because the supplicants gather at the altar located at the front of the church building. In the old testament, an altar was where sacrifices were made. So, the name "altar call" refers to a believer "offering" themselves on an altar to God, as in Romans 12:1 I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service.
Most altar calls occur at the end of an evangelical address. The invitation may be referred to as an "altar call" even if there is no actual altar present. Many preachers make use of the altar call; notable examples include Billy Graham, Benny Hinn, Franklin Graham and Reinhard Bonnke. Congregations often sing a hymn, usually with a theme of invitation or decision, during the altar call. Some churches makes use of the sinner's prayer, which people who come forward to be "saved" are asked to recite. It is sometimes said that those who come forth are going to receive Jesus Christ as their Savior. This is a ritual in which the supplicant makes a prayer asking for his sins to be forgiven, acknowledges Jesus as the risen Son of God and pledges his/her devotion to Jesus and to live thereafter following Christ's teachings. This is often called being born again.
In Pentecostal churches, the altar is a place people can come and repent of their sins and pray to receive the Holy Spirit, which they believe is accompanied with the initial sign of speaking in tongues. It is also a place to go to pray for needs and to get a "touch" from God. Pentecostal altar calls often involve the laying on of hands, and many people will come up to pray for others to receive their need. Altar calls may also invite Christians to come forward for specific purposes other than conversion; for example to rededicate their lives after a lapse, to pray for healing, to surrender a new part of their lives to God, or to receive a particular blessing. It is also a place of dedication where callings are given (such as a call to the ministry).
To be blunt, this process has nothing to do with the gospel message of the New Testament. There is no New Testament sanction for an ‘altar located at the front of the church building’ whether real or imaginary. It is a practice introduced by apostate Christianity. There is no New Testament precedent for responding to an ‘altar call’ to be ‘saved’. The ‘church’ is the congregation not a building. The altar of the congregation is Christ. To respond to the call of Christ we must believe the gospel and be baptised by immersion in water. In Romans 12:1 (above) Paul is speaking to baptised believers.
The teaching of scripture is clear:
Mark 16:15 And he said unto them, Go ye into all the world, and preach the gospel to every creature. 16 He that believeth and is baptized shall be saved;
In order to believe one has to have reached an age of understanding. This varies with individuals from approximately 13 years and upwards. The individual concerned must make his own freewill decision to be baptised into Christ for the remission of their sins with a full comprehension of what this means. The decision must be voluntary and baptism administered following a full confession of faith. There is no value in an emotional ‘spur of the moment’ response to a charismatic address.
Parents are required to bring up their children in the nurture and admonition of the Lord.
Ephesians 6:4 And, ye fathers, provoke not your children to wrath: but bring them up in the nurture and admonition of the Lord.
This means that children should be given a proper understanding of what the Bible actually teaches rather than being indoctrinated with traditional church teaching.
Until they reach an age of understanding, children are sanctified by the belief and obedience to the true gospel of one or both parents.
1 Corinthians 7:14 For the unbelieving husband is sanctified by the wife, and the unbelieving wife is sanctified by the husband: else were your children unclean; but now are they holy.
The best that you can do for your child is to teach him the true gospel of Christ and give him the space to make his own decision when he is of an age to understand the commitment required.
I hope you have found this helpful.
May God bless you,