Bible Doctrine is critical

Scriptural doctrine
2Tim. 3:16 All Scripture is inspired by God and profitable for teaching, for reproof, for correction, for training in righteousness;
determines where we will spend our eternal future
2 John 1:9 - Anyone who goes too far and does not abide in the teaching of Christ, does not have God; the one who abides in the teaching, he has both the Father and the Son.
our behavior
2Tim. 3:10 - Now you followed my teaching, conduct, purpose, faith, patience, love, perseverance,
preserves the integrity of the Gospel
Gal. 2:5 But we did not yield in subjection to them for even an hour, so that the truth of the gospel would remain with you.
edifies believers and maintains unity of the faith
Titus 1:9 - holding fast the faithful word which is in accordance with the teaching, so that he will be able both to exhort in sound doctrine and to refute those who contradict.
and is essential for our maturity in Christ
Hebrews 5:14 - But solid food is for the mature, who because of practice have their senses trained to discern good and evil.

Yes our Bible doctrine is important because how we believe is directly linked to how we behave!
"The unattended garden will soon be overrun with weeds; the heart that fails to cultivate truth and root out error will shortly be a theological wilderness." (A.W. Tozer, Man: The Dwelling Place of God)