We see in Ephesians 4:14 that we are not to be infants who are "tossed back and forth by the waves, and blown here and there by every wind of teaching." Infants, in this context, are those who are influenced by teaching that contradicts the core truth of Christian faith. Such teaching comes from those who practice trickery for selfish gain.
I wonder, though, if the phrase "every wind of teaching" might also include that which is not hard-core heresy, but simply misguided or distracting. As a pastor, I have occasionally counseled people who rejected basic Christian faith. But, far more commonly, I have dealt with those who were surfing the wave of the latest trendy theology or philosophy. In some cases, they fell under the influence of a popular media preacher whose theology was questionable at best. In other cases, the disturbing wind came from a secular guru. Even if the spiritual infants didn't abandon their faith, their lives became focused on something other than the gospel of Jesus Christ and its implications. Thus, they were tossed around in their faith and life.
The use of the metaphor of infants implies that spiritually immature people are not able to make themselves grow up. Real babies depend on others to feed them, clothe them, and protect them. So it is with believers who are young in the faith. They need to be instructed and equipped by spiritual leaders, especially pastor-teachers (4:11). But the responsibility for helping immature believers falls not only upon the identified leaders but also upon the whole church. (See Eph. 4:16 and 1 Cor. 12-14.)
All of us begin our Christian lives as "infants," no matter our chronological age. God intends for each of us to grow up as the body of Christ does its work in our lives. As we grow into maturity, we become those who teach and nurture others, so that they—and the whole body—might grow up in Christ (Eph. 4:15).