Is it necessary if you trade for instance on one hour chart to look at higher timeframes for entrance
Its a helpful guide. Beware of taking a direction from the 1-hour bars that lie in the Asian/Australasian session, when both London and New York are closed. Trading still occurs then but volumes are much lower and the price action is less of a help. Cross-check on at least the 4-hourly time-frame, maybe daily might work better.
It is really helpful to look at higher timeframes. Take for instance your H1 is in an uptrend, which would prompt you to buy the pair with confidence, only for the market to suddenly reverse before reaching your target. What you missed might be the fact that the good looking uptrend on the H1 was simply a retracement on the daily timeframe and has come to a major daily resistance that would see the market continue downwards.
On the H1 timeframe, it would be a reversal, but on the daily timeframe, it simply is a continuation of the downtrend. So, looking at higher timeframes helps you to locate your position in the market, and make informed decisions based on your location.
A combination of 2 timeframes is always better. One as the main, and a lower or higher time-frame as a complementing one. You will get more accurate predictions.
I find it better to look at high time frames. They are easier to interpret and offer better information.