In order to explain Christianity correctly you have to be able to direct people to a Church which will lead them to Heaven.

You're not explaining Christianity correctly if you are promoting a false church lost in heresy which drags people down to eternal perdition!

First off...

1 - Is Christianity a lie, a scam, a fraud? Is Jesus a false god, a false Messiah?

2 - Is Christianity the True Faith which leads people to Heaven?  Is Jesus the Divine Son of Psalm 2 and Isaiah 9. 6?

Suppose Christianity is the True Faith, as we Christians insist. Then, moving onwards...

The scriptures are clear there is one True Church.  See John 15. 23-26 and Matthew 16.13-19.  St. Paul's phrase "there is one body" in Ephesians 4. 4 means there is one True Church.

Consider the Roman Catholic Church.  Rome is either God's True Church or else Rome is not God's True Church. Rome either leads people to Heaven or else Rome does not lead people to Heaven.

The same 2 options apply to every Christian denomination.

The Mormon Church either leads people to Heaven or else the Mormon Church does not lead people to Heaven.

The Russian Orthodox Church either leads people to Heaven or else the Russian Orthodox Church does not lead people to Heaven.

If you tell people that a specific church will deliver them to Heaven, when in fact that church you are promoting is a false church lost in heresy which drags people down to eternal perdition, then you are a heretic, because you are leading people to perdition, by promoting a false church, and so you are on the road to perdition, and so you need to repent and stop being a heretic in order to escape perdition.

2 Thess 2 says the Antichrist shows up prior to the Second Coming of Christ.

Revelation 14. 6-11 says 3 angels from Heaven will show up.

Suppose an angel shows up. Suppose this angel says the Church of England and only the Church of England is God's True Church which leads people to Heaven. 

Suppose that angel says that every other Christian denomination, and every Non-Christian religion, leads people to eternal perdition.

So, if that angel is speaking the truth, then he must be an angel from Heaven, assuming he never slips into heresy.

But if that angel is telling an evil lie, if in fact the Church of England is a false church lost in heresy, a scam church which drags people down to eternal perdition, then that angel is leading people to perdition, so he must be an angel from Hell, provided he never repents.

So, unless you already know with 100% accuracy, how to identify God's True Church, you might not be able to determine, should an angel show up, if that angel is an angel from Hell or if he is an angel from Heaven.