The Catholic Church is composed of over 1 billion members worldwide of with 58 millions residing in America.
The Catholic Church is a mixture of Christianity with Paganism. It believes many of the things that Christians believe in, but also other things which come straight out of pagan religions.
Some of its false doctrines are the worship of the Virgin Mary, Purgatory, Idol worship, the Papal authority, Penance, and many others.
Catholics have been taught that Protestants despise the Virgin Mary, But that is not so. We respect and admire Mary for her submission to God, and her motherhood of Jesus our Lord. However we do not worship her, nor do we grant her the title mother of God.
Purgatory is nowhere mentioned in the Bible, it is a doctrine without any foundation. This doctrine also takes away the completeness of Jesus redemption for us.
Idol worship is a breaking of the second commandment of God. In spite of the protest of some Catholic apologists, who insist that their images are only to help the believer, to concentrate in his devotion. Kneeling or prostrating before an idol does constitute worship.
The authority of the church of God does not rest upon any single individual. The Papal authority is a self-proclaimed right with no scriptural or moral validity.
Jesus Christ has completely paid for all our sins, whether they be past, present, or future. Any attempt to add to his sacrifice either through penance, special offerings or good works is totally wrong.
There are many other areas where the Catholic church errs, but these will suffice to show that this is not the church that Christ established.
Are all Catholics lost? I don't know, but since the Catholic church is indeed the whore of Babylon, mentioned in the book of Revelation, then the best thing a Catholic can do is to come out of her; like God says to do, lest he also be a partaker of the plagues that will fall upon her (Revelation 18:4)
Reaching out to Catholics should not be hard, the best thing is to start in the areas where we do agree with them, and work from there.
Many Catholics will not attend a protestant church, because the Pope has decreed it to be a mortal sin, for which there is no forgiveness, so the best thing is to reach them through a home ministry, in other words going to them
One can start by using a Catholic Bible which is not much different than the protestant, except for some added books.
Many of them are just Catholic in name; consequently the depth of their commitment to that church is very shallow indeed.
Reaching out to them is not hard. The tremendous growth of the protestant church in Latin America is proof of that.
We must avoid a spirit of condemnation or strife. We do not want to alienate them, but to bring them to the power of Christ saving grace.