What is freedom? Jesus makes clear that it is submission to God which creates freedom from sin. Paul emphasizes this freedom as we begin Galatians 5. In relationship with God (in and through Jesus) we transcend the limitations of God's Instruction (Torah/Law). Paul demands clarity on this--Gentiles remain Gentiles, even in Christ. Jesus is Savior, He gives the Spirit. He does what the Torah cannot. (Romans explains this more deeply).
Paul spells out the implications of adding circumcision to faith. If Gentiles want to turn from Jesus to Torah, then they need to read the fine print, "you are obligated to keep the whole law (1:3)." However, the freedom in Jesus does not mean freedom to sin; rather it is freedom to love. Love is not optional in the Kingdom, nor is ethical behavior. The Holy Spirit of God is at enmity with sinful 'sarx/flesh' so behaviors still matter. The natural state of humans is sin, we are alienated from God. God graciously breaks through that that alienation, but we are still required to live in accord with the covenant expectations. We cannot make ourselves right with God, we receive mercy, however, mercy begins the process of living in the Kingdom. Faith is not a passive magic escape from obedience... The importance of human behavior is clearly spelled out in 5:20-21: "those who live like this will not inherit the Kingdom of God." Some of the listed sins are not things we engage in (debauchery, idolatry & witchcraft) but most are pretty common place: discord, jealousy, rage, selfish ambition, dissension, envy and sexual immorality.
"If you cause conflicts or envy others you will not inherit the Kingdom?" This verse needs to be balanced by what else is said, but it does seem to imply that "if you cannot earn your salvation by what you do, it seems that what you do can cause you to lose salvation."
Chapter six continue with this line of thought: "a man reaps what he sows." This reinforces the organic nature of life, including faith. You become what your choices make you (choose flesh or Spirit). Faith necessarily includes choosing the Spirit, if you believe/trust Jesus then you are living in/according to God's Spirit. "Doing good" is repeated by Paul, because if he minimizes the role of the Torah for Gentiles, he does not negate doing good--faith is obedient and love is the way of life.
So if I believe in Jesus but do not love, do I believe in Jesus? It seems not. I think when we read Galatians we must remember that the human person can be spoken of in segments (mind, body, soul) but in reality the human is not separate parts, but a whole. My thoughts, beliefs, feelings, desires are not housed in isolated sections. They interact, overlap and interpenetrate.
What I believe affects what I think and desire and feel. How I feel effects my thought. Faith in Jesus is trust, it trusts Him for salvation (not Torah, not circumcision). Being saved by grace means God does something for us which we can never earn. We are given free admission into His Kingdom. Once there, however, we need to understand the Kingdom ethic. Perhaps the parable of the wedding garment from Matthew will help here. The messengers went out to the highways and bi-ways and brought in the previously univited. The invitation is always pure grace. But there was a man without a wedding garment who was cast out (garment in Revelation is good deeds)! Grace, works...
The Biblical concepts need to interact. Take seriously your conversion in response to His grace. Understand the behavioral component of trusting Jesus. Paul did. If at times Paul is hard to understand (cf 2 Peter 3:15-16) it has always been so. Life is not simple.