All my life i read the account of the pair beening driven from the garden. I always took it that the cheribums were to block and keep them from turning back.
I was so wrong.
God placed them there to keep the path open so they COULD return to him. And that is our pathway back to God being kept open for whosoever will.
My opinion
In Genesis 3:22-24, the reason why the cherubim were placed to guard the way to the Tree of Life is clearly stated to block access to the Tree of Life, so you were correct, however, guarding the way to the Tree of Life can refer either to blocking access or to providing escort, so you are also correct that God placed them there to keep the path open so they could return to Him. In Genesis 2:15, God placed Adam in the garden to guard it, so the cherubim were placed in he garden for the same purpose that he was and he was never told to cease from doing that from outside of the garden.
Before Adam and Eve had eaten from either tree, they were at a crossroads between morality and eternal life, where eating from the Tree of Knowledge of Good and Evil caused them to become mortal while eating from the Tree of life would have caused them to have eternal life. In Deuteronomy 30:15-20, the Israelites were at the same crossroads where Moses presented a choice between life and death, life and a blessing for guarding God's commandments or death and curse for not guarding them. In Exodus 33:13, Moses wanted God to be gracious to him by teaching to him by teaching him to walk in His way that he might know Him and Israel too, and in Matthew 7:23, Jesus said that he would tell those who are workers of lawlessness to depart from him because he never knew them, so the goal of the Torah is to teach us how to have the experience of knowing God and Jesus, which is the way to eternal life (John 17:3).
There are a number of ways where Eve's desire influenced her perception (Genesis 3:6), and our desire clouds our judgement so that we can no longer be sure if something is truly good or if we just think that it is good because we desire it, so this is where we have the choice of whether we are going to do what is right in our own eyes in accordance with eating from the Tree of Knowledge of Good and Evil or whether we are going to choose to undo the damage that was caused by eating from that tree by leaning not on our own understanding and instead trusting in God with all of our heart to correctly divide between right and wrong through obeying what He has instructed, in all of our ways acknowledge him, and and He will make our way straight (Proverbs 3:1-6). She is a Tree of Life for all who take hold of her (Proverbs 3:16-18).
The cherubim were also placed on the Ark of the Covenant to guard the Torah, God repeatedly instructed the Israelites to guard its commandments, and there are many verses along this theme of angels, guarding, the way, the Tree of Life, the Torah, and to or from Jerusalem. For example, in Exodus 23:20, God will send an angel before them to guard them on the way and to bring them to the place that He has prepared, and in Luke 10:25-30, Jesus responded to a question about the way to inherit eternal life by affirming obedience to the greatest two commandments of the Torah and then giving a parable about a man on the way from Jerusalem, so that was not an incidental detail. Likewise, Paul was also on the way from Jerusalem to persecute members of "The Way", so it is much more important that he was on the way from Jerusalem than that he was on the road to Damascus. In Revelation 22:14, those who obeyed God's commandments are given the right to eat from the Tree of Life, so the whole Bible is essentially about the way back to the Tree of Life.
