Do we go to Hell if we backslide in our faith? Yes and no. Many people in Calvinist, Arminian, and even in Christian Universalist circles don't rightly divide the difference between what 1John 2 calls little children in Christ (irrespective of biological age), and as all translations will vary there's an implication next of an adolescent level of Christianity, and then there's spiritual adulthood or what 1John 2 would call fathers in the faith. These ideas carry throughout the whole New Testament though with different phrases and particularly different ways in which each translator will handle them.
A little child in Christ regards one only after the flesh according to 1st and 2nd Corinthians, an adolescent would regard no one after the flesh according to 2Corinthians 5:16, and a spiritual father would regard one after both the flesh and in the Lord according to Philemon 1:16. The spiritual father differs from the little child in that the child will regard one after the flesh in a worldly manner while the spiritual father will regard one after the pattern of 1Thessalonians 5:23 with anticipating the sanctification of spirit, soul, and body.
An adolescent believes many things from the Scriptures that are only transitional truths, and may find much private discomfort in alleged inconsistencies, though they may believe many of the transitional truths that they hold to, to be absolute truths, while the spiritual father will see the consistency of absolutely all of the Scriptures. Briefly, an example of a transitional truth is that the flesh profits nothing, yet Romans 8:11, 1Thessalonians 5:23, Philemon 1:16, Hebrews 5:12-14, and many, many other passages will look to the reclaiming of the flesh as a spiritual instrument. Origen would have heaped the undying worms and the fire that's not quenched as a transitional truth 'cause there's Scripture that'll yet eclipse that with yet a higher mountain peak of greater truth for those that are ready.
With that said, there is the matter of Hebrews 6 that talks of those that have walked in all of the manifestations of harvesting all 9 of their Galatians 5 fruit and of the 1Corinthians 12 gifts of the Spirit together with the solid food of the Word of God, and yet reach the point where it's impossible to bring them to repentance where they essentially wind up being in the same category as the fallen one in Ezekiel 28 and Isaiah 14. The only salvation for someone that's morphed themselves into a minister of Satan and knows what they were doing as they started doing it is after long ages after they've gone into the Lake of Fire.
But the Hebrews 6 and Hebrews 10 sin of trodding under foot the Blood of the Covenant and bringing fierce aggravation to the Spirit of Grace can't be committed by a spiritual baby or by a spiritual teenager 'cause our heavenly Father knows the difference between a big mouth kid and an adult in spiritual things that needs his mouth washed out with some lava because they didn't heed the parable of the sower's warnings and allowed themselves to become offended at very very advanced stages of the game. But some Assemblies of God pastors and evangelists and a few members of other groups will try to make the sins of a spiritual adult for whom there remains no more sacrifice for sins into the plight of what someone that's still struggling with their fleshly appetites and an unrenewed mind and that's nothing but the grief of the Holy Spirit in Ephesians 4 as far as Holy Spirit is concerned.
He's not going to punish the natural man, the little child in spiritual things, or a spiritual adolescent on the level that He'll deal with an absolute equal in absolutely all things that knows that they're there and through an offended heart steps across that line in telling Him and the Church to go to Hell. 1John says to not even pray for someone like that. This is one on one between Him and them and He's going to be in their face perpetually until He's purged that sin from their lives. But although it's a fearful thing to fall into the hands of the living God, as the author of the book of Hebrews says, David said in the Old Testament (2Samuel 24:14; 1Chronicles 21:13) that it's MUCH BETTER to fall into the LORD's hands than into the hands of man -- which couldn't be true if Eternal torment, or Eternal separation, or Eternal annihilation were true.