Sharing your faith with your son is not complicated. It doesn't take huge quantities of time. Sharing your faith with your son is about frequency and consistency.
Even before we begin with the process, however, we need to understand a huge error in thinking for many fathers, that is based on the poor teaching and modeling they received, in particular in American culture. It's kind of like our dirty little secret. Here is the formula.
Spiritual= Women
Let me be more specific and say fathers in American society who identify as "Christian," fall into this trap all the time. These dads (you, who are reading this right now, may be one of them ) pray, pray at meals, acknowledge faith in Jesus, may participate in some faith practices at home, and may occasionally attend church activities. Yet, even among these dads, nurturing the faith of their children is considered mom's responsibility.
If there are any faith practices in the home they are almost always initiated and led my mom. Bedtime prayers- mom-led. On the rare occasion that children are brought to church activities (4% of people in their 20's/ 15% of people in their 30's are regularly connected to faith communities, today in America), they are most often brought by their mothers alone.
If you are an active part of a Christian community you have seen "spiritual widows"- women who are active in a church community without their husbands, carrying out their faith nurturing role alone. On the one hand, you admire their efforts, on the other, you ask yourself, "Where's dad?"