Teaching is the profession that creates all others. But if teachers can only provide contents, facts, dates, formulas, research, theories and stories – information that can be easily forgotten after the “test”, then, their role in the lives of the students become obsolete and success on students’ part will become hard to achieve. Challenges of the 21st Century Teachers Indeed, teacher’s task is fulfilling yet daunting. Thus, this paper will focus on the possible solutions to address the challenges of the 21st century teachers in terms of the teacher’s effectiveness in the new learning paradigm. And then, it is imperative to ask and answer the questions: what are the new skills required to succeed in this current era; and how can they be taught effectively to students so that after finishing K-12, every graduate will be ready to go into different paths like further education, employment or entrepreneurship. These challenges are brought about by change and social development. In every change there is conflict and it does not happen overnight. In every conflict there will be realizations that will enable the stakeholders to resolve the tensions brought about by change. No education is perfect. However, since K-12 is a controversial new curriculum in the Philippines, every Filipino, most especially teachers, should know the 21st century skills, and how teaching and learning process must be different from that of the past. Teaching Effectiveness Teaching effectiveness is a tricky concept to comprehend. Marland, in Kivunja (2014) said that “Teaching effectiveness varies according to time, place and the learners in the classroom. What is effective for one teacher will not work for another teacher. What is effective in Grade I will certainly not be effective in Grade 6 or Grade 12. What is effective in this era will not be effective in the next. Teaching effectiveness varies from teacher to teacher, class to class and from one era to the next.” Graham (2015) says, “As teachers, it is our responsibility to model and teach how to be effective and efficient twenty-first century learners while also being safe and legally responsible. At the same time, our students have to master our curriculum’s content and learn how to demonstrate that understanding on standardized tests. In every way this is overwhelming, which is I believe that finding a balanced way to incorporate technology into what we are already doing in order to make teaching more effective is the key to preparing our students for their lives outside the school”. He also added that looking at social media sites as a tool may help us connect with our students and serve to increase our effectiveness in engaging them in our content. Trilling and Fadel (2009), in Kivunja (2014) stressed that for teachers to be effective and to equip students with the skills that will enable them to be successful, productive citizens in the Digital Economy, it is essential to teach them not just the tra