It would be great if this really was all that is needed to become a child of God, but every devout Roman Catholic I know that reads this would come out feeling convinced that they are a child of God.
This article lacks any mention of sin or repentance, but both Jesus and Paul were very careful to not leave those teachings out of their gospel messages.
Yes, a child of God becomes a partaker in the inheritance, but Paul had this to say about how that is secured;
1 Corinthians 6:9 (KJV)
Know ye not that the unrighteous shall not inherit the kingdom of God? Be not deceived: neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor abusers of themselves with mankind, Nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners, shall inherit the kingdom of God.
Notice he didn't say "the unbelievers shall not inherit.."
Jesus also laying down a little more understanding of what it means to believe in and follow him;
Matthew 19:29 (KJV) And every one that hath forsaken houses, or brethren, or sisters, or father, or mother, or wife, or children, or lands, for my name's sake, shall receive an hundredfold, and shall inherit everlasting life.
So our inheritance may be secure, but it comes with a cost and it is not free, nor will it be easy to maintain.
If a Roman Catholic who is steeped in idolatry and false teaching can come out of reading an article feeling vindicated, you may want to go back and rewrite it to add in the details that are required for such a glorious title.
Mark