"Are you so foolish? Having begun by the Spirit, are you now being perfected by the flesh? Did you suffer so many things in vain—if indeed it was in vain? Does he who supplies the Spirit to you and works miracles among you do so by works of the law, or by hearing with faith—just as Abraham “believed God, and it was counted to him as righteousness”? Gal 3:3-6 (ESV).
The Galatians had a dangerous tendency to depend on religious rituals to make themselves feel right with God. Paul wrote to remind them that it is not religious rituals that makes them right with God, but faith.
The Galatians were becoming strict adherents of a clear, Old Testament teaching, circumcision. Abraham was the patriarch of the Israelites who was given the promise and told to circumcise himself and all of the males with him (Genesis 17:1-14). The Old Testament was clear that those who were not circumcised were excluded from the promise (Genesis 17:14).
The fulfillment of that Old Testament covenant in Jesus changed things. No longer was a religious ritual necessary to be right with God, it was now faith: Not just an intellectual faith that causes one to participate in religious rituals or abstain from short-term actions but a faith that spurs us on toward loving those around us. Abstaining from selfish actions is painful because they produce short-term pleasure. Refraining from relying on religious rituals is difficult because the ritual provides comfort and stability. But love is where it's at. Love is how we move further on the tight rope toward who God designed us to be, not refusing to be selfish or adhering to rituals.
"For freedom Christ has set us free; stand firm therefore, and do not submit again to a yoke of slavery...For in Christ Jesus neither circumcision nor uncircumcision counts for anything, but only faith working through love...For you were called to freedom, brothers. Only do not use your freedom as an opportunity for the flesh, but through love serve one another. For the whole law is fulfilled in one word: “You shall love your neighbor as yourself” (Galatians 5:1,6, 13-14).
We're not called to be hermits. We can enjoy the pleasures of life that God has blessed us with and we can find joy and encouragement in religious rituals, but when they keep us from moving forward in love, they become sin and prevent us from the life God has intended for us to live.